Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

43 files changed, 18981 insertions, 0 deletions

diff --git a/third_party/python/setuptools/pkg_resources/__init__.py b/third_party/python/setuptools/pkg_resources/__init__.py
new file mode 100644
index 0000000000..3fc97af475
--- /dev/null
+++ b/third_party/python/setuptools/pkg_resources/__init__.py
@@ -0,0 +1,3361 @@
+"""
+Package resource API
+--------------------
+
+A resource is a logical file contained within a package, or a logical
+subdirectory thereof.  The package resource API expects resource names
+to have their path parts separated with ``/``, *not* whatever the local
+path separator is.  Do not use os.path operations to manipulate resource
+names being passed into the API.
+
+The package resource API is designed to work with normal filesystem packages,
+.egg files, and unpacked .egg files.  It can also work in a limited way with
+.zip files and with custom PEP 302 loaders that support the ``get_data()``
+method.
+
+This module is deprecated. Users are directed to :mod:`importlib.resources`,
+:mod:`importlib.metadata` and :pypi:`packaging` instead.
+"""
+
+import sys
+import os
+import io
+import time
+import re
+import types
+import zipfile
+import zipimport
+import warnings
+import stat
+import functools
+import pkgutil
+import operator
+import platform
+import collections
+import plistlib
+import email.parser
+import errno
+import tempfile
+import textwrap
+import inspect
+import ntpath
+import posixpath
+import importlib
+from pkgutil import get_importer
+
+try:
+    import _imp
+except ImportError:
+    # Python 3.2 compatibility
+    import imp as _imp
+
+try:
+    FileExistsError
+except NameError:
+    FileExistsError = OSError
+
+# capture these to bypass sandboxing
+from os import utime
+
+try:
+    from os import mkdir, rename, unlink
+
+    WRITE_SUPPORT = True
+except ImportError:
+    # no write support, probably under GAE
+    WRITE_SUPPORT = False
+
+from os import open as os_open
+from os.path import isdir, split
+
+try:
+    import importlib.machinery as importlib_machinery
+
+    # access attribute to force import under delayed import mechanisms.
+    importlib_machinery.__name__
+except ImportError:
+    importlib_machinery = None
+
+from pkg_resources.extern.jaraco.text import (
+    yield_lines,
+    drop_comment,
+    join_continuation,
+)
+
+from pkg_resources.extern import platformdirs
+from pkg_resources.extern import packaging
+
+__import__('pkg_resources.extern.packaging.version')
+__import__('pkg_resources.extern.packaging.specifiers')
+__import__('pkg_resources.extern.packaging.requirements')
+__import__('pkg_resources.extern.packaging.markers')
+__import__('pkg_resources.extern.packaging.utils')
+
+if sys.version_info < (3, 5):
+    raise RuntimeError("Python 3.5 or later is required")
+
+# declare some globals that will be defined later to
+# satisfy the linters.
+require = None
+working_set = None
+add_activation_listener = None
+resources_stream = None
+cleanup_resources = None
+resource_dir = None
+resource_stream = None
+set_extraction_path = None
+resource_isdir = None
+resource_string = None
+iter_entry_points = None
+resource_listdir = None
+resource_filename = None
+resource_exists = None
+_distribution_finders = None
+_namespace_handlers = None
+_namespace_packages = None
+
+
+warnings.warn(
+    "pkg_resources is deprecated as an API. "
+    "See https://setuptools.pypa.io/en/latest/pkg_resources.html",
+    DeprecationWarning,
+    stacklevel=2
+)
+
+
+_PEP440_FALLBACK = re.compile(r"^v?(?P<safe>(?:[0-9]+!)?[0-9]+(?:\.[0-9]+)*)", re.I)
+
+
+class PEP440Warning(RuntimeWarning):
+    """
+    Used when there is an issue with a version or specifier not complying with
+    PEP 440.
+    """
+
+
+parse_version = packaging.version.Version
+
+
+_state_vars = {}
+
+
+def _declare_state(vartype, **kw):
+    globals().update(kw)
+    _state_vars.update(dict.fromkeys(kw, vartype))
+
+
+def __getstate__():
+    state = {}
+    g = globals()
+    for k, v in _state_vars.items():
+        state[k] = g['_sget_' + v](g[k])
+    return state
+
+
+def __setstate__(state):
+    g = globals()
+    for k, v in state.items():
+        g['_sset_' + _state_vars[k]](k, g[k], v)
+    return state
+
+
+def _sget_dict(val):
+    return val.copy()
+
+
+def _sset_dict(key, ob, state):
+    ob.clear()
+    ob.update(state)
+
+
+def _sget_object(val):
+    return val.__getstate__()
+
+
+def _sset_object(key, ob, state):
+    ob.__setstate__(state)
+
+
+_sget_none = _sset_none = lambda *args: None
+
+
+def get_supported_platform():
+    """Return this platform's maximum compatible version.
+
+    distutils.util.get_platform() normally reports the minimum version
+    of macOS that would be required to *use* extensions produced by
+    distutils.  But what we want when checking compatibility is to know the
+    version of macOS that we are *running*.  To allow usage of packages that
+    explicitly require a newer version of macOS, we must also know the
+    current version of the OS.
+
+    If this condition occurs for any other platform with a version in its
+    platform strings, this function should be extended accordingly.
+    """
+    plat = get_build_platform()
+    m = macosVersionString.match(plat)
+    if m is not None and sys.platform == "darwin":
+        try:
+            plat = 'macosx-%s-%s' % ('.'.join(_macos_vers()[:2]), m.group(3))
+        except ValueError:
+            # not macOS
+            pass
+    return plat
+
+
+__all__ = [
+    # Basic resource access and distribution/entry point discovery
+    'require',
+    'run_script',
+    'get_provider',
+    'get_distribution',
+    'load_entry_point',
+    'get_entry_map',
+    'get_entry_info',
+    'iter_entry_points',
+    'resource_string',
+    'resource_stream',
+    'resource_filename',
+    'resource_listdir',
+    'resource_exists',
+    'resource_isdir',
+    # Environmental control
+    'declare_namespace',
+    'working_set',
+    'add_activation_listener',
+    'find_distributions',
+    'set_extraction_path',
+    'cleanup_resources',
+    'get_default_cache',
+    # Primary implementation classes
+    'Environment',
+    'WorkingSet',
+    'ResourceManager',
+    'Distribution',
+    'Requirement',
+    'EntryPoint',
+    # Exceptions
+    'ResolutionError',
+    'VersionConflict',
+    'DistributionNotFound',
+    'UnknownExtra',
+    'ExtractionError',
+    # Warnings
+    'PEP440Warning',
+    # Parsing functions and string utilities
+    'parse_requirements',
+    'parse_version',
+    'safe_name',
+    'safe_version',
+    'get_platform',
+    'compatible_platforms',
+    'yield_lines',
+    'split_sections',
+    'safe_extra',
+    'to_filename',
+    'invalid_marker',
+    'evaluate_marker',
+    # filesystem utilities
+    'ensure_directory',
+    'normalize_path',
+    # Distribution "precedence" constants
+    'EGG_DIST',
+    'BINARY_DIST',
+    'SOURCE_DIST',
+    'CHECKOUT_DIST',
+    'DEVELOP_DIST',
+    # "Provider" interfaces, implementations, and registration/lookup APIs
+    'IMetadataProvider',
+    'IResourceProvider',
+    'FileMetadata',
+    'PathMetadata',
+    'EggMetadata',
+    'EmptyProvider',
+    'empty_provider',
+    'NullProvider',
+    'EggProvider',
+    'DefaultProvider',
+    'ZipProvider',
+    'register_finder',
+    'register_namespace_handler',
+    'register_loader_type',
+    'fixup_namespace_packages',
+    'get_importer',
+    # Warnings
+    'PkgResourcesDeprecationWarning',
+    # Deprecated/backward compatibility only
+    'run_main',
+    'AvailableDistributions',
+]
+
+
+class ResolutionError(Exception):
+    """Abstract base for dependency resolution errors"""
+
+    def __repr__(self):
+        return self.__class__.__name__ + repr(self.args)
+
+
+class VersionConflict(ResolutionError):
+    """
+    An already-installed version conflicts with the requested version.
+
+    Should be initialized with the installed Distribution and the requested
+    Requirement.
+    """
+
+    _template = "{self.dist} is installed but {self.req} is required"
+
+    @property
+    def dist(self):
+        return self.args[0]
+
+    @property
+    def req(self):
+        return self.args[1]
+
+    def report(self):
+        return self._template.format(**locals())
+
+    def with_context(self, required_by):
+        """
+        If required_by is non-empty, return a version of self that is a
+        ContextualVersionConflict.
+        """
+        if not required_by:
+            return self
+        args = self.args + (required_by,)
+        return ContextualVersionConflict(*args)
+
+
+class ContextualVersionConflict(VersionConflict):
+    """
+    A VersionConflict that accepts a third parameter, the set of the
+    requirements that required the installed Distribution.
+    """
+
+    _template = VersionConflict._template + ' by {self.required_by}'
+
+    @property
+    def required_by(self):
+        return self.args[2]
+
+
+class DistributionNotFound(ResolutionError):
+    """A requested distribution was not found"""
+
+    _template = (
+        "The '{self.req}' distribution was not found "
+        "and is required by {self.requirers_str}"
+    )
+
+    @property
+    def req(self):
+        return self.args[0]
+
+    @property
+    def requirers(self):
+        return self.args[1]
+
+    @property
+    def requirers_str(self):
+        if not self.requirers:
+            return 'the application'
+        return ', '.join(self.requirers)
+
+    def report(self):
+        return self._template.format(**locals())
+
+    def __str__(self):
+        return self.report()
+
+
+class UnknownExtra(ResolutionError):
+    """Distribution doesn't have an "extra feature" of the given name"""
+
+
+_provider_factories = {}
+
+PY_MAJOR = '{}.{}'.format(*sys.version_info)
+EGG_DIST = 3
+BINARY_DIST = 2
+SOURCE_DIST = 1
+CHECKOUT_DIST = 0
+DEVELOP_DIST = -1
+
+
+def register_loader_type(loader_type, provider_factory):
+    """Register `provider_factory` to make providers for `loader_type`
+
+    `loader_type` is the type or class of a PEP 302 ``module.__loader__``,
+    and `provider_factory` is a function that, passed a *module* object,
+    returns an ``IResourceProvider`` for that module.
+    """
+    _provider_factories[loader_type] = provider_factory
+
+
+def get_provider(moduleOrReq):
+    """Return an IResourceProvider for the named module or requirement"""
+    if isinstance(moduleOrReq, Requirement):
+        return working_set.find(moduleOrReq) or require(str(moduleOrReq))[0]
+    try:
+        module = sys.modules[moduleOrReq]
+    except KeyError:
+        __import__(moduleOrReq)
+        module = sys.modules[moduleOrReq]
+    loader = getattr(module, '__loader__', None)
+    return _find_adapter(_provider_factories, loader)(module)
+
+
+def _macos_vers(_cache=[]):
+    if not _cache:
+        version = platform.mac_ver()[0]
+        # fallback for MacPorts
+        if version == '':
+            plist = '/System/Library/CoreServices/SystemVersion.plist'
+            if os.path.exists(plist):
+                if hasattr(plistlib, 'readPlist'):
+                    plist_content = plistlib.readPlist(plist)
+                    if 'ProductVersion' in plist_content:
+                        version = plist_content['ProductVersion']
+
+        _cache.append(version.split('.'))
+    return _cache[0]
+
+
+def _macos_arch(machine):
+    return {'PowerPC': 'ppc', 'Power_Macintosh': 'ppc'}.get(machine, machine)
+
+
+def get_build_platform():
+    """Return this platform's string for platform-specific distributions
+
+    XXX Currently this is the same as ``distutils.util.get_platform()``, but it
+    needs some hacks for Linux and macOS.
+    """
+    from sysconfig import get_platform
+
+    plat = get_platform()
+    if sys.platform == "darwin" and not plat.startswith('macosx-'):
+        try:
+            version = _macos_vers()
+            machine = os.uname()[4].replace(" ", "_")
+            return "macosx-%d.%d-%s" % (
+                int(version[0]),
+                int(version[1]),
+                _macos_arch(machine),
+            )
+        except ValueError:
+            # if someone is running a non-Mac darwin system, this will fall
+            # through to the default implementation
+            pass
+    return plat
+
+
+macosVersionString = re.compile(r"macosx-(\d+)\.(\d+)-(.*)")
+darwinVersionString = re.compile(r"darwin-(\d+)\.(\d+)\.(\d+)-(.*)")
+# XXX backward compat
+get_platform = get_build_platform
+
+
+def compatible_platforms(provided, required):
+    """Can code for the `provided` platform run on the `required` platform?
+
+    Returns true if either platform is ``None``, or the platforms are equal.
+
+    XXX Needs compatibility checks for Linux and other unixy OSes.
+    """
+    if provided is None or required is None or provided == required:
+        # easy case
+        return True
+
+    # macOS special cases
+    reqMac = macosVersionString.match(required)
+    if reqMac:
+        provMac = macosVersionString.match(provided)
+
+        # is this a Mac package?
+        if not provMac:
+            # this is backwards compatibility for packages built before
+            # setuptools 0.6. All packages built after this point will
+            # use the new macOS designation.
+            provDarwin = darwinVersionString.match(provided)
+            if provDarwin:
+                dversion = int(provDarwin.group(1))
+                macosversion = "%s.%s" % (reqMac.group(1), reqMac.group(2))
+                if (
+                    dversion == 7
+                    and macosversion >= "10.3"
+                    or dversion == 8
+                    and macosversion >= "10.4"
+                ):
+                    return True
+            # egg isn't macOS or legacy darwin
+            return False
+
+        # are they the same major version and machine type?
+        if provMac.group(1) != reqMac.group(1) or provMac.group(3) != reqMac.group(3):
+            return False
+
+        # is the required OS major update >= the provided one?
+        if int(provMac.group(2)) > int(reqMac.group(2)):
+            return False
+
+        return True
+
+    # XXX Linux and other platforms' special cases should go here
+    return False
+
+
+def run_script(dist_spec, script_name):
+    """Locate distribution `dist_spec` and run its `script_name` script"""
+    ns = sys._getframe(1).f_globals
+    name = ns['__name__']
+    ns.clear()
+    ns['__name__'] = name
+    require(dist_spec)[0].run_script(script_name, ns)
+
+
+# backward compatibility
+run_main = run_script
+
+
+def get_distribution(dist):
+    """Return a current distribution object for a Requirement or string"""
+    if isinstance(dist, str):
+        dist = Requirement.parse(dist)
+    if isinstance(dist, Requirement):
+        dist = get_provider(dist)
+    if not isinstance(dist, Distribution):
+        raise TypeError("Expected string, Requirement, or Distribution", dist)
+    return dist
+
+
+def load_entry_point(dist, group, name):
+    """Return `name` entry point of `group` for `dist` or raise ImportError"""
+    return get_distribution(dist).load_entry_point(group, name)
+
+
+def get_entry_map(dist, group=None):
+    """Return the entry point map for `group`, or the full entry map"""
+    return get_distribution(dist).get_entry_map(group)
+
+
+def get_entry_info(dist, group, name):
+    """Return the EntryPoint object for `group`+`name`, or ``None``"""
+    return get_distribution(dist).get_entry_info(group, name)
+
+
+class IMetadataProvider:
+    def has_metadata(name):
+        """Does the package's distribution contain the named metadata?"""
+
+    def get_metadata(name):
+        """The named metadata resource as a string"""
+
+    def get_metadata_lines(name):
+        """Yield named metadata resource as list of non-blank non-comment lines
+
+        Leading and trailing whitespace is stripped from each line, and lines
+        with ``#`` as the first non-blank character are omitted."""
+
+    def metadata_isdir(name):
+        """Is the named metadata a directory?  (like ``os.path.isdir()``)"""
+
+    def metadata_listdir(name):
+        """List of metadata names in the directory (like ``os.listdir()``)"""
+
+    def run_script(script_name, namespace):
+        """Execute the named script in the supplied namespace dictionary"""
+
+
+class IResourceProvider(IMetadataProvider):
+    """An object that provides access to package resources"""
+
+    def get_resource_filename(manager, resource_name):
+        """Return a true filesystem path for `resource_name`
+
+        `manager` must be an ``IResourceManager``"""
+
+    def get_resource_stream(manager, resource_name):
+        """Return a readable file-like object for `resource_name`
+
+        `manager` must be an ``IResourceManager``"""
+
+    def get_resource_string(manager, resource_name):
+        """Return a string containing the contents of `resource_name`
+
+        `manager` must be an ``IResourceManager``"""
+
+    def has_resource(resource_name):
+        """Does the package contain the named resource?"""
+
+    def resource_isdir(resource_name):
+        """Is the named resource a directory?  (like ``os.path.isdir()``)"""
+
+    def resource_listdir(resource_name):
+        """List of resource names in the directory (like ``os.listdir()``)"""
+
+
+class WorkingSet:
+    """A collection of active distributions on sys.path (or a similar list)"""
+
+    def __init__(self, entries=None):
+        """Create working set from list of path entries (default=sys.path)"""
+        self.entries = []
+        self.entry_keys = {}
+        self.by_key = {}
+        self.normalized_to_canonical_keys = {}
+        self.callbacks = []
+
+        if entries is None:
+            entries = sys.path
+
+        for entry in entries:
+            self.add_entry(entry)
+
+    @classmethod
+    def _build_master(cls):
+        """
+        Prepare the master working set.
+        """
+        ws = cls()
+        try:
+            from __main__ import __requires__
+        except ImportError:
+            # The main program does not list any requirements
+            return ws
+
+        # ensure the requirements are met
+        try:
+            ws.require(__requires__)
+        except VersionConflict:
+            return cls._build_from_requirements(__requires__)
+
+        return ws
+
+    @classmethod
+    def _build_from_requirements(cls, req_spec):
+        """
+        Build a working set from a requirement spec. Rewrites sys.path.
+        """
+        # try it without defaults already on sys.path
+        # by starting with an empty path
+        ws = cls([])
+        reqs = parse_requirements(req_spec)
+        dists = ws.resolve(reqs, Environment())
+        for dist in dists:
+            ws.add(dist)
+
+        # add any missing entries from sys.path
+        for entry in sys.path:
+            if entry not in ws.entries:
+                ws.add_entry(entry)
+
+        # then copy back to sys.path
+        sys.path[:] = ws.entries
+        return ws
+
+    def add_entry(self, entry):
+        """Add a path item to ``.entries``, finding any distributions on it
+
+        ``find_distributions(entry, True)`` is used to find distributions
+        corresponding to the path entry, and they are added.  `entry` is
+        always appended to ``.entries``, even if it is already present.
+        (This is because ``sys.path`` can contain the same value more than
+        once, and the ``.entries`` of the ``sys.path`` WorkingSet should always
+        equal ``sys.path``.)
+        """
+        self.entry_keys.setdefault(entry, [])
+        self.entries.append(entry)
+        for dist in find_distributions(entry, True):
+            self.add(dist, entry, False)
+
+    def __contains__(self, dist):
+        """True if `dist` is the active distribution for its project"""
+        return self.by_key.get(dist.key) == dist
+
+    def find(self, req):
+        """Find a distribution matching requirement `req`
+
+        If there is an active distribution for the requested project, this
+        returns it as long as it meets the version requirement specified by
+        `req`.  But, if there is an active distribution for the project and it
+        does *not* meet the `req` requirement, ``VersionConflict`` is raised.
+        If there is no active distribution for the requested project, ``None``
+        is returned.
+        """
+        dist = self.by_key.get(req.key)
+
+        if dist is None:
+            canonical_key = self.normalized_to_canonical_keys.get(req.key)
+
+            if canonical_key is not None:
+                req.key = canonical_key
+                dist = self.by_key.get(canonical_key)
+
+        if dist is not None and dist not in req:
+            # XXX add more info
+            raise VersionConflict(dist, req)
+        return dist
+
+    def iter_entry_points(self, group, name=None):
+        """Yield entry point objects from `group` matching `name`
+
+        If `name` is None, yields all entry points in `group` from all
+        distributions in the working set, otherwise only ones matching
+        both `group` and `name` are yielded (in distribution order).
+        """
+        return (
+            entry
+            for dist in self
+            for entry in dist.get_entry_map(group).values()
+            if name is None or name == entry.name
+        )
+
+    def run_script(self, requires, script_name):
+        """Locate distribution for `requires` and run `script_name` script"""
+        ns = sys._getframe(1).f_globals
+        name = ns['__name__']
+        ns.clear()
+        ns['__name__'] = name
+        self.require(requires)[0].run_script(script_name, ns)
+
+    def __iter__(self):
+        """Yield distributions for non-duplicate projects in the working set
+
+        The yield order is the order in which the items' path entries were
+        added to the working set.
+        """
+        seen = {}
+        for item in self.entries:
+            if item not in self.entry_keys:
+                # workaround a cache issue
+                continue
+
+            for key in self.entry_keys[item]:
+                if key not in seen:
+                    seen[key] = 1
+                    yield self.by_key[key]
+
+    def add(self, dist, entry=None, insert=True, replace=False):
+        """Add `dist` to working set, associated with `entry`
+
+        If `entry` is unspecified, it defaults to the ``.location`` of `dist`.
+        On exit from this routine, `entry` is added to the end of the working
+        set's ``.entries`` (if it wasn't already present).
+
+        `dist` is only added to the working set if it's for a project that
+        doesn't already have a distribution in the set, unless `replace=True`.
+        If it's added, any callbacks registered with the ``subscribe()`` method
+        will be called.
+        """
+        if insert:
+            dist.insert_on(self.entries, entry, replace=replace)
+
+        if entry is None:
+            entry = dist.location
+        keys = self.entry_keys.setdefault(entry, [])
+        keys2 = self.entry_keys.setdefault(dist.location, [])
+        if not replace and dist.key in self.by_key:
+            # ignore hidden distros
+            return
+
+        self.by_key[dist.key] = dist
+        normalized_name = packaging.utils.canonicalize_name(dist.key)
+        self.normalized_to_canonical_keys[normalized_name] = dist.key
+        if dist.key not in keys:
+            keys.append(dist.key)
+        if dist.key not in keys2:
+            keys2.append(dist.key)
+        self._added_new(dist)
+
+    def resolve(
+        self,
+        requirements,
+        env=None,
+        installer=None,
+        replace_conflicting=False,
+        extras=None,
+    ):
+        """List all distributions needed to (recursively) meet `requirements`
+
+        `requirements` must be a sequence of ``Requirement`` objects.  `env`,
+        if supplied, should be an ``Environment`` instance.  If
+        not supplied, it defaults to all distributions available within any
+        entry or distribution in the working set.  `installer`, if supplied,
+        will be invoked with each requirement that cannot be met by an
+        already-installed distribution; it should return a ``Distribution`` or
+        ``None``.
+
+        Unless `replace_conflicting=True`, raises a VersionConflict exception
+        if
+        any requirements are found on the path that have the correct name but
+        the wrong version.  Otherwise, if an `installer` is supplied it will be
+        invoked to obtain the correct version of the requirement and activate
+        it.
+
+        `extras` is a list of the extras to be used with these requirements.
+        This is important because extra requirements may look like `my_req;
+        extra = "my_extra"`, which would otherwise be interpreted as a purely
+        optional requirement.  Instead, we want to be able to assert that these
+        requirements are truly required.
+        """
+
+        # set up the stack
+        requirements = list(requirements)[::-1]
+        # set of processed requirements
+        processed = {}
+        # key -> dist
+        best = {}
+        to_activate = []
+
+        req_extras = _ReqExtras()
+
+        # Mapping of requirement to set of distributions that required it;
+        # useful for reporting info about conflicts.
+        required_by = collections.defaultdict(set)
+
+        while requirements:
+            # process dependencies breadth-first
+            req = requirements.pop(0)
+            if req in processed:
+                # Ignore cyclic or redundant dependencies
+                continue
+
+            if not req_extras.markers_pass(req, extras):
+                continue
+
+            dist = self._resolve_dist(
+                req, best, replace_conflicting, env, installer, required_by, to_activate
+            )
+
+            # push the new requirements onto the stack
+            new_requirements = dist.requires(req.extras)[::-1]
+            requirements.extend(new_requirements)
+
+            # Register the new requirements needed by req
+            for new_requirement in new_requirements:
+                required_by[new_requirement].add(req.project_name)
+                req_extras[new_requirement] = req.extras
+
+            processed[req] = True
+
+        # return list of distros to activate
+        return to_activate
+
+    def _resolve_dist(
+        self, req, best, replace_conflicting, env, installer, required_by, to_activate
+    ):
+        dist = best.get(req.key)
+        if dist is None:
+            # Find the best distribution and add it to the map
+            dist = self.by_key.get(req.key)
+            if dist is None or (dist not in req and replace_conflicting):
+                ws = self
+                if env is None:
+                    if dist is None:
+                        env = Environment(self.entries)
+                    else:
+                        # Use an empty environment and workingset to avoid
+                        # any further conflicts with the conflicting
+                        # distribution
+                        env = Environment([])
+                        ws = WorkingSet([])
+                dist = best[req.key] = env.best_match(
+                    req, ws, installer, replace_conflicting=replace_conflicting
+                )
+                if dist is None:
+                    requirers = required_by.get(req, None)
+                    raise DistributionNotFound(req, requirers)
+            to_activate.append(dist)
+        if dist not in req:
+            # Oops, the "best" so far conflicts with a dependency
+            dependent_req = required_by[req]
+            raise VersionConflict(dist, req).with_context(dependent_req)
+        return dist
+
+    def find_plugins(self, plugin_env, full_env=None, installer=None, fallback=True):
+        """Find all activatable distributions in `plugin_env`
+
+        Example usage::
+
+            distributions, errors = working_set.find_plugins(
+                Environment(plugin_dirlist)
+            )
+            # add plugins+libs to sys.path
+            map(working_set.add, distributions)
+            # display errors
+            print('Could not load', errors)
+
+        The `plugin_env` should be an ``Environment`` instance that contains
+        only distributions that are in the project's "plugin directory" or
+        directories. The `full_env`, if supplied, should be an ``Environment``
+        contains all currently-available distributions.  If `full_env` is not
+        supplied, one is created automatically from the ``WorkingSet`` this
+        method is called on, which will typically mean that every directory on
+        ``sys.path`` will be scanned for distributions.
+
+        `installer` is a standard installer callback as used by the
+        ``resolve()`` method. The `fallback` flag indicates whether we should
+        attempt to resolve older versions of a plugin if the newest version
+        cannot be resolved.
+
+        This method returns a 2-tuple: (`distributions`, `error_info`), where
+        `distributions` is a list of the distributions found in `plugin_env`
+        that were loadable, along with any other distributions that are needed
+        to resolve their dependencies.  `error_info` is a dictionary mapping
+        unloadable plugin distributions to an exception instance describing the
+        error that occurred. Usually this will be a ``DistributionNotFound`` or
+        ``VersionConflict`` instance.
+        """
+
+        plugin_projects = list(plugin_env)
+        # scan project names in alphabetic order
+        plugin_projects.sort()
+
+        error_info = {}
+        distributions = {}
+
+        if full_env is None:
+            env = Environment(self.entries)
+            env += plugin_env
+        else:
+            env = full_env + plugin_env
+
+        shadow_set = self.__class__([])
+        # put all our entries in shadow_set
+        list(map(shadow_set.add, self))
+
+        for project_name in plugin_projects:
+            for dist in plugin_env[project_name]:
+                req = [dist.as_requirement()]
+
+                try:
+                    resolvees = shadow_set.resolve(req, env, installer)
+
+                except ResolutionError as v:
+                    # save error info
+                    error_info[dist] = v
+                    if fallback:
+                        # try the next older version of project
+                        continue
+                    else:
+                        # give up on this project, keep going
+                        break
+
+                else:
+                    list(map(shadow_set.add, resolvees))
+                    distributions.update(dict.fromkeys(resolvees))
+
+                    # success, no need to try any more versions of this project
+                    break
+
+        distributions = list(distributions)
+        distributions.sort()
+
+        return distributions, error_info
+
+    def require(self, *requirements):
+        """Ensure that distributions matching `requirements` are activated
+
+        `requirements` must be a string or a (possibly-nested) sequence
+        thereof, specifying the distributions and versions required.  The
+        return value is a sequence of the distributions that needed to be
+        activated to fulfill the requirements; all relevant distributions are
+        included, even if they were already activated in this working set.
+        """
+        needed = self.resolve(parse_requirements(requirements))
+
+        for dist in needed:
+            self.add(dist)
+
+        return needed
+
+    def subscribe(self, callback, existing=True):
+        """Invoke `callback` for all distributions
+
+        If `existing=True` (default),
+        call on all existing ones, as well.
+        """
+        if callback in self.callbacks:
+            return
+        self.callbacks.append(callback)
+        if not existing:
+            return
+        for dist in self:
+            callback(dist)
+
+    def _added_new(self, dist):
+        for callback in self.callbacks:
+            callback(dist)
+
+    def __getstate__(self):
+        return (
+            self.entries[:],
+            self.entry_keys.copy(),
+            self.by_key.copy(),
+            self.normalized_to_canonical_keys.copy(),
+            self.callbacks[:],
+        )
+
+    def __setstate__(self, e_k_b_n_c):
+        entries, keys, by_key, normalized_to_canonical_keys, callbacks = e_k_b_n_c
+        self.entries = entries[:]
+        self.entry_keys = keys.copy()
+        self.by_key = by_key.copy()
+        self.normalized_to_canonical_keys = normalized_to_canonical_keys.copy()
+        self.callbacks = callbacks[:]
+
+
+class _ReqExtras(dict):
+    """
+    Map each requirement to the extras that demanded it.
+    """
+
+    def markers_pass(self, req, extras=None):
+        """
+        Evaluate markers for req against each extra that
+        demanded it.
+
+        Return False if the req has a marker and fails
+        evaluation. Otherwise, return True.
+        """
+        extra_evals = (
+            req.marker.evaluate({'extra': extra})
+            for extra in self.get(req, ()) + (extras or (None,))
+        )
+        return not req.marker or any(extra_evals)
+
+
+class Environment:
+    """Searchable snapshot of distributions on a search path"""
+
+    def __init__(
+        self, search_path=None, platform=get_supported_platform(), python=PY_MAJOR
+    ):
+        """Snapshot distributions available on a search path
+
+        Any distributions found on `search_path` are added to the environment.
+        `search_path` should be a sequence of ``sys.path`` items.  If not
+        supplied, ``sys.path`` is used.
+
+        `platform` is an optional string specifying the name of the platform
+        that platform-specific distributions must be compatible with.  If
+        unspecified, it defaults to the current platform.  `python` is an
+        optional string naming the desired version of Python (e.g. ``'3.6'``);
+        it defaults to the current version.
+
+        You may explicitly set `platform` (and/or `python`) to ``None`` if you
+        wish to map *all* distributions, not just those compatible with the
+        running platform or Python version.
+        """
+        self._distmap = {}
+        self.platform = platform
+        self.python = python
+        self.scan(search_path)
+
+    def can_add(self, dist):
+        """Is distribution `dist` acceptable for this environment?
+
+        The distribution must match the platform and python version
+        requirements specified when this environment was created, or False
+        is returned.
+        """
+        py_compat = (
+            self.python is None
+            or dist.py_version is None
+            or dist.py_version == self.python
+        )
+        return py_compat and compatible_platforms(dist.platform, self.platform)
+
+    def remove(self, dist):
+        """Remove `dist` from the environment"""
+        self._distmap[dist.key].remove(dist)
+
+    def scan(self, search_path=None):
+        """Scan `search_path` for distributions usable in this environment
+
+        Any distributions found are added to the environment.
+        `search_path` should be a sequence of ``sys.path`` items.  If not
+        supplied, ``sys.path`` is used.  Only distributions conforming to
+        the platform/python version defined at initialization are added.
+        """
+        if search_path is None:
+            search_path = sys.path
+
+        for item in search_path:
+            for dist in find_distributions(item):
+                self.add(dist)
+
+    def __getitem__(self, project_name):
+        """Return a newest-to-oldest list of distributions for `project_name`
+
+        Uses case-insensitive `project_name` comparison, assuming all the
+        project's distributions use their project's name converted to all
+        lowercase as their key.
+
+        """
+        distribution_key = project_name.lower()
+        return self._distmap.get(distribution_key, [])
+
+    def add(self, dist):
+        """Add `dist` if we ``can_add()`` it and it has not already been added"""
+        if self.can_add(dist) and dist.has_version():
+            dists = self._distmap.setdefault(dist.key, [])
+            if dist not in dists:
+                dists.append(dist)
+                dists.sort(key=operator.attrgetter('hashcmp'), reverse=True)
+
+    def best_match(self, req, working_set, installer=None, replace_conflicting=False):
+        """Find distribution best matching `req` and usable on `working_set`
+
+        This calls the ``find(req)`` method of the `working_set` to see if a
+        suitable distribution is already active.  (This may raise
+        ``VersionConflict`` if an unsuitable version of the project is already
+        active in the specified `working_set`.)  If a suitable distribution
+        isn't active, this method returns the newest distribution in the
+        environment that meets the ``Requirement`` in `req`.  If no suitable
+        distribution is found, and `installer` is supplied, then the result of
+        calling the environment's ``obtain(req, installer)`` method will be
+        returned.
+        """
+        try:
+            dist = working_set.find(req)
+        except VersionConflict:
+            if not replace_conflicting:
+                raise
+            dist = None
+        if dist is not None:
+            return dist
+        for dist in self[req.key]:
+            if dist in req:
+                return dist
+        # try to download/install
+        return self.obtain(req, installer)
+
+    def obtain(self, requirement, installer=None):
+        """Obtain a distribution matching `requirement` (e.g. via download)
+
+        Obtain a distro that matches requirement (e.g. via download).  In the
+        base ``Environment`` class, this routine just returns
+        ``installer(requirement)``, unless `installer` is None, in which case
+        None is returned instead.  This method is a hook that allows subclasses
+        to attempt other ways of obtaining a distribution before falling back
+        to the `installer` argument."""
+        if installer is not None:
+            return installer(requirement)
+
+    def __iter__(self):
+        """Yield the unique project names of the available distributions"""
+        for key in self._distmap.keys():
+            if self[key]:
+                yield key
+
+    def __iadd__(self, other):
+        """In-place addition of a distribution or environment"""
+        if isinstance(other, Distribution):
+            self.add(other)
+        elif isinstance(other, Environment):
+            for project in other:
+                for dist in other[project]:
+                    self.add(dist)
+        else:
+            raise TypeError("Can't add %r to environment" % (other,))
+        return self
+
+    def __add__(self, other):
+        """Add an environment or distribution to an environment"""
+        new = self.__class__([], platform=None, python=None)
+        for env in self, other:
+            new += env
+        return new
+
+
+# XXX backward compatibility
+AvailableDistributions = Environment
+
+
+class ExtractionError(RuntimeError):
+    """An error occurred extracting a resource
+
+    The following attributes are available from instances of this exception:
+
+    manager
+        The resource manager that raised this exception
+
+    cache_path
+        The base directory for resource extraction
+
+    original_error
+        The exception instance that caused extraction to fail
+    """
+
+
+class ResourceManager:
+    """Manage resource extraction and packages"""
+
+    extraction_path = None
+
+    def __init__(self):
+        self.cached_files = {}
+
+    def resource_exists(self, package_or_requirement, resource_name):
+        """Does the named resource exist?"""
+        return get_provider(package_or_requirement).has_resource(resource_name)
+
+    def resource_isdir(self, package_or_requirement, resource_name):
+        """Is the named resource an existing directory?"""
+        return get_provider(package_or_requirement).resource_isdir(resource_name)
+
+    def resource_filename(self, package_or_requirement, resource_name):
+        """Return a true filesystem path for specified resource"""
+        return get_provider(package_or_requirement).get_resource_filename(
+            self, resource_name
+        )
+
+    def resource_stream(self, package_or_requirement, resource_name):
+        """Return a readable file-like object for specified resource"""
+        return get_provider(package_or_requirement).get_resource_stream(
+            self, resource_name
+        )
+
+    def resource_string(self, package_or_requirement, resource_name):
+        """Return specified resource as a string"""
+        return get_provider(package_or_requirement).get_resource_string(
+            self, resource_name
+        )
+
+    def resource_listdir(self, package_or_requirement, resource_name):
+        """List the contents of the named resource directory"""
+        return get_provider(package_or_requirement).resource_listdir(resource_name)
+
+    def extraction_error(self):
+        """Give an error message for problems extracting file(s)"""
+
+        old_exc = sys.exc_info()[1]
+        cache_path = self.extraction_path or get_default_cache()
+
+        tmpl = textwrap.dedent(
+            """
+            Can't extract file(s) to egg cache
+
+            The following error occurred while trying to extract file(s)
+            to the Python egg cache:
+
+              {old_exc}
+
+            The Python egg cache directory is currently set to:
+
+              {cache_path}
+
+            Perhaps your account does not have write access to this directory?
+            You can change the cache directory by setting the PYTHON_EGG_CACHE
+            environment variable to point to an accessible directory.
+            """
+        ).lstrip()
+        err = ExtractionError(tmpl.format(**locals()))
+        err.manager = self
+        err.cache_path = cache_path
+        err.original_error = old_exc
+        raise err
+
+    def get_cache_path(self, archive_name, names=()):
+        """Return absolute location in cache for `archive_name` and `names`
+
+        The parent directory of the resulting path will be created if it does
+        not already exist.  `archive_name` should be the base filename of the
+        enclosing egg (which may not be the name of the enclosing zipfile!),
+        including its ".egg" extension.  `names`, if provided, should be a
+        sequence of path name parts "under" the egg's extraction location.
+
+        This method should only be called by resource providers that need to
+        obtain an extraction location, and only for names they intend to
+        extract, as it tracks the generated names for possible cleanup later.
+        """
+        extract_path = self.extraction_path or get_default_cache()
+        target_path = os.path.join(extract_path, archive_name + '-tmp', *names)
+        try:
+            _bypass_ensure_directory(target_path)
+        except Exception:
+            self.extraction_error()
+
+        self._warn_unsafe_extraction_path(extract_path)
+
+        self.cached_files[target_path] = 1
+        return target_path
+
+    @staticmethod
+    def _warn_unsafe_extraction_path(path):
+        """
+        If the default extraction path is overridden and set to an insecure
+        location, such as /tmp, it opens up an opportunity for an attacker to
+        replace an extracted file with an unauthorized payload. Warn the user
+        if a known insecure location is used.
+
+        See Distribute #375 for more details.
+        """
+        if os.name == 'nt' and not path.startswith(os.environ['windir']):
+            # On Windows, permissions are generally restrictive by default
+            #  and temp directories are not writable by other users, so
+            #  bypass the warning.
+            return
+        mode = os.stat(path).st_mode
+        if mode & stat.S_IWOTH or mode & stat.S_IWGRP:
+            msg = (
+                "Extraction path is writable by group/others "
+                "and vulnerable to attack when "
+                "used with get_resource_filename ({path}). "
+                "Consider a more secure "
+                "location (set with .set_extraction_path or the "
+                "PYTHON_EGG_CACHE environment variable)."
+            ).format(**locals())
+            warnings.warn(msg, UserWarning)
+
+    def postprocess(self, tempname, filename):
+        """Perform any platform-specific postprocessing of `tempname`
+
+        This is where Mac header rewrites should be done; other platforms don't
+        have anything special they should do.
+
+        Resource providers should call this method ONLY after successfully
+        extracting a compressed resource.  They must NOT call it on resources
+        that are already in the filesystem.
+
+        `tempname` is the current (temporary) name of the file, and `filename`
+        is the name it will be renamed to by the caller after this routine
+        returns.
+        """
+
+        if os.name == 'posix':
+            # Make the resource executable
+            mode = ((os.stat(tempname).st_mode) | 0o555) & 0o7777
+            os.chmod(tempname, mode)
+
+    def set_extraction_path(self, path):
+        """Set the base path where resources will be extracted to, if needed.
+
+        If you do not call this routine before any extractions take place, the
+        path defaults to the return value of ``get_default_cache()``.  (Which
+        is based on the ``PYTHON_EGG_CACHE`` environment variable, with various
+        platform-specific fallbacks.  See that routine's documentation for more
+        details.)
+
+        Resources are extracted to subdirectories of this path based upon
+        information given by the ``IResourceProvider``.  You may set this to a
+        temporary directory, but then you must call ``cleanup_resources()`` to
+        delete the extracted files when done.  There is no guarantee that
+        ``cleanup_resources()`` will be able to remove all extracted files.
+
+        (Note: you may not change the extraction path for a given resource
+        manager once resources have been extracted, unless you first call
+        ``cleanup_resources()``.)
+        """
+        if self.cached_files:
+            raise ValueError("Can't change extraction path, files already extracted")
+
+        self.extraction_path = path
+
+    def cleanup_resources(self, force=False):
+        """
+        Delete all extracted resource files and directories, returning a list
+        of the file and directory names that could not be successfully removed.
+        This function does not have any concurrency protection, so it should
+        generally only be called when the extraction path is a temporary
+        directory exclusive to a single process.  This method is not
+        automatically called; you must call it explicitly or register it as an
+        ``atexit`` function if you wish to ensure cleanup of a temporary
+        directory used for extractions.
+        """
+        # XXX
+
+
+def get_default_cache():
+    """
+    Return the ``PYTHON_EGG_CACHE`` environment variable
+    or a platform-relevant user cache dir for an app
+    named "Python-Eggs".
+    """
+    return os.environ.get('PYTHON_EGG_CACHE') or platformdirs.user_cache_dir(
+        appname='Python-Eggs'
+    )
+
+
+def safe_name(name):
+    """Convert an arbitrary string to a standard distribution name
+
+    Any runs of non-alphanumeric/. characters are replaced with a single '-'.
+    """
+    return re.sub('[^A-Za-z0-9.]+', '-', name)
+
+
+def safe_version(version):
+    """
+    Convert an arbitrary string to a standard version string
+    """
+    try:
+        # normalize the version
+        return str(packaging.version.Version(version))
+    except packaging.version.InvalidVersion:
+        version = version.replace(' ', '.')
+        return re.sub('[^A-Za-z0-9.]+', '-', version)
+
+
+def _forgiving_version(version):
+    """Fallback when ``safe_version`` is not safe enough
+    >>> parse_version(_forgiving_version('0.23ubuntu1'))
+    <Version('0.23.dev0+sanitized.ubuntu1')>
+    >>> parse_version(_forgiving_version('0.23-'))
+    <Version('0.23.dev0+sanitized')>
+    >>> parse_version(_forgiving_version('0.-_'))
+    <Version('0.dev0+sanitized')>
+    >>> parse_version(_forgiving_version('42.+?1'))
+    <Version('42.dev0+sanitized.1')>
+    >>> parse_version(_forgiving_version('hello world'))
+    <Version('0.dev0+sanitized.hello.world')>
+    """
+    version = version.replace(' ', '.')
+    match = _PEP440_FALLBACK.search(version)
+    if match:
+        safe = match["safe"]
+        rest = version[len(safe):]
+    else:
+        safe = "0"
+        rest = version
+    local = f"sanitized.{_safe_segment(rest)}".strip(".")
+    return f"{safe}.dev0+{local}"
+
+
+def _safe_segment(segment):
+    """Convert an arbitrary string into a safe segment"""
+    segment = re.sub('[^A-Za-z0-9.]+', '-', segment)
+    segment = re.sub('-[^A-Za-z0-9]+', '-', segment)
+    return re.sub(r'\.[^A-Za-z0-9]+', '.', segment).strip(".-")
+
+
+def safe_extra(extra):
+    """Convert an arbitrary string to a standard 'extra' name
+
+    Any runs of non-alphanumeric characters are replaced with a single '_',
+    and the result is always lowercased.
+    """
+    return re.sub('[^A-Za-z0-9.-]+', '_', extra).lower()
+
+
+def to_filename(name):
+    """Convert a project or version name to its filename-escaped form
+
+    Any '-' characters are currently replaced with '_'.
+    """
+    return name.replace('-', '_')
+
+
+def invalid_marker(text):
+    """
+    Validate text as a PEP 508 environment marker; return an exception
+    if invalid or False otherwise.
+    """
+    try:
+        evaluate_marker(text)
+    except SyntaxError as e:
+        e.filename = None
+        e.lineno = None
+        return e
+    return False
+
+
+def evaluate_marker(text, extra=None):
+    """
+    Evaluate a PEP 508 environment marker.
+    Return a boolean indicating the marker result in this environment.
+    Raise SyntaxError if marker is invalid.
+
+    This implementation uses the 'pyparsing' module.
+    """
+    try:
+        marker = packaging.markers.Marker(text)
+        return marker.evaluate()
+    except packaging.markers.InvalidMarker as e:
+        raise SyntaxError(e) from e
+
+
+class NullProvider:
+    """Try to implement resources and metadata for arbitrary PEP 302 loaders"""
+
+    egg_name = None
+    egg_info = None
+    loader = None
+
+    def __init__(self, module):
+        self.loader = getattr(module, '__loader__', None)
+        self.module_path = os.path.dirname(getattr(module, '__file__', ''))
+
+    def get_resource_filename(self, manager, resource_name):
+        return self._fn(self.module_path, resource_name)
+
+    def get_resource_stream(self, manager, resource_name):
+        return io.BytesIO(self.get_resource_string(manager, resource_name))
+
+    def get_resource_string(self, manager, resource_name):
+        return self._get(self._fn(self.module_path, resource_name))
+
+    def has_resource(self, resource_name):
+        return self._has(self._fn(self.module_path, resource_name))
+
+    def _get_metadata_path(self, name):
+        return self._fn(self.egg_info, name)
+
+    def has_metadata(self, name):
+        if not self.egg_info:
+            return self.egg_info
+
+        path = self._get_metadata_path(name)
+        return self._has(path)
+
+    def get_metadata(self, name):
+        if not self.egg_info:
+            return ""
+        path = self._get_metadata_path(name)
+        value = self._get(path)
+        try:
+            return value.decode('utf-8')
+        except UnicodeDecodeError as exc:
+            # Include the path in the error message to simplify
+            # troubleshooting, and without changing the exception type.
+            exc.reason += ' in {} file at path: {}'.format(name, path)
+            raise
+
+    def get_metadata_lines(self, name):
+        return yield_lines(self.get_metadata(name))
+
+    def resource_isdir(self, resource_name):
+        return self._isdir(self._fn(self.module_path, resource_name))
+
+    def metadata_isdir(self, name):
+        return self.egg_info and self._isdir(self._fn(self.egg_info, name))
+
+    def resource_listdir(self, resource_name):
+        return self._listdir(self._fn(self.module_path, resource_name))
+
+    def metadata_listdir(self, name):
+        if self.egg_info:
+            return self._listdir(self._fn(self.egg_info, name))
+        return []
+
+    def run_script(self, script_name, namespace):
+        script = 'scripts/' + script_name
+        if not self.has_metadata(script):
+            raise ResolutionError(
+                "Script {script!r} not found in metadata at {self.egg_info!r}".format(
+                    **locals()
+                ),
+            )
+        script_text = self.get_metadata(script).replace('\r\n', '\n')
+        script_text = script_text.replace('\r', '\n')
+        script_filename = self._fn(self.egg_info, script)
+        namespace['__file__'] = script_filename
+        if os.path.exists(script_filename):
+            with open(script_filename) as fid:
+                source = fid.read()
+            code = compile(source, script_filename, 'exec')
+            exec(code, namespace, namespace)
+        else:
+            from linecache import cache
+
+            cache[script_filename] = (
+                len(script_text),
+                0,
+                script_text.split('\n'),
+                script_filename,
+            )
+            script_code = compile(script_text, script_filename, 'exec')
+            exec(script_code, namespace, namespace)
+
+    def _has(self, path):
+        raise NotImplementedError(
+            "Can't perform this operation for unregistered loader type"
+        )
+
+    def _isdir(self, path):
+        raise NotImplementedError(
+            "Can't perform this operation for unregistered loader type"
+        )
+
+    def _listdir(self, path):
+        raise NotImplementedError(
+            "Can't perform this operation for unregistered loader type"
+        )
+
+    def _fn(self, base, resource_name):
+        self._validate_resource_path(resource_name)
+        if resource_name:
+            return os.path.join(base, *resource_name.split('/'))
+        return base
+
+    @staticmethod
+    def _validate_resource_path(path):
+        """
+        Validate the resource paths according to the docs.
+        https://setuptools.pypa.io/en/latest/pkg_resources.html#basic-resource-access
+
+        >>> warned = getfixture('recwarn')
+        >>> warnings.simplefilter('always')
+        >>> vrp = NullProvider._validate_resource_path
+        >>> vrp('foo/bar.txt')
+        >>> bool(warned)
+        False
+        >>> vrp('../foo/bar.txt')
+        >>> bool(warned)
+        True
+        >>> warned.clear()
+        >>> vrp('/foo/bar.txt')
+        >>> bool(warned)
+        True
+        >>> vrp('foo/../../bar.txt')
+        >>> bool(warned)
+        True
+        >>> warned.clear()
+        >>> vrp('foo/f../bar.txt')
+        >>> bool(warned)
+        False
+
+        Windows path separators are straight-up disallowed.
+        >>> vrp(r'\\foo/bar.txt')
+        Traceback (most recent call last):
+        ...
+        ValueError: Use of .. or absolute path in a resource path \
+is not allowed.
+
+        >>> vrp(r'C:\\foo/bar.txt')
+        Traceback (most recent call last):
+        ...
+        ValueError: Use of .. or absolute path in a resource path \
+is not allowed.
+
+        Blank values are allowed
+
+        >>> vrp('')
+        >>> bool(warned)
+        False
+
+        Non-string values are not.
+
+        >>> vrp(None)
+        Traceback (most recent call last):
+        ...
+        AttributeError: ...
+        """
+        invalid = (
+            os.path.pardir in path.split(posixpath.sep)
+            or posixpath.isabs(path)
+            or ntpath.isabs(path)
+        )
+        if not invalid:
+            return
+
+        msg = "Use of .. or absolute path in a resource path is not allowed."
+
+        # Aggressively disallow Windows absolute paths
+        if ntpath.isabs(path) and not posixpath.isabs(path):
+            raise ValueError(msg)
+
+        # for compatibility, warn; in future
+        # raise ValueError(msg)
+        issue_warning(
+            msg[:-1] + " and will raise exceptions in a future release.",
+            DeprecationWarning,
+        )
+
+    def _get(self, path):
+        if hasattr(self.loader, 'get_data'):
+            return self.loader.get_data(path)
+        raise NotImplementedError(
+            "Can't perform this operation for loaders without 'get_data()'"
+        )
+
+
+register_loader_type(object, NullProvider)
+
+
+def _parents(path):
+    """
+    yield all parents of path including path
+    """
+    last = None
+    while path != last:
+        yield path
+        last = path
+        path, _ = os.path.split(path)
+
+
+class EggProvider(NullProvider):
+    """Provider based on a virtual filesystem"""
+
+    def __init__(self, module):
+        super().__init__(module)
+        self._setup_prefix()
+
+    def _setup_prefix(self):
+        # Assume that metadata may be nested inside a "basket"
+        # of multiple eggs and use module_path instead of .archive.
+        eggs = filter(_is_egg_path, _parents(self.module_path))
+        egg = next(eggs, None)
+        egg and self._set_egg(egg)
+
+    def _set_egg(self, path):
+        self.egg_name = os.path.basename(path)
+        self.egg_info = os.path.join(path, 'EGG-INFO')
+        self.egg_root = path
+
+
+class DefaultProvider(EggProvider):
+    """Provides access to package resources in the filesystem"""
+
+    def _has(self, path):
+        return os.path.exists(path)
+
+    def _isdir(self, path):
+        return os.path.isdir(path)
+
+    def _listdir(self, path):
+        return os.listdir(path)
+
+    def get_resource_stream(self, manager, resource_name):
+        return open(self._fn(self.module_path, resource_name), 'rb')
+
+    def _get(self, path):
+        with open(path, 'rb') as stream:
+            return stream.read()
+
+    @classmethod
+    def _register(cls):
+        loader_names = (
+            'SourceFileLoader',
+            'SourcelessFileLoader',
+        )
+        for name in loader_names:
+            loader_cls = getattr(importlib_machinery, name, type(None))
+            register_loader_type(loader_cls, cls)
+
+
+DefaultProvider._register()
+
+
+class EmptyProvider(NullProvider):
+    """Provider that returns nothing for all requests"""
+
+    module_path = None
+
+    _isdir = _has = lambda self, path: False
+
+    def _get(self, path):
+        return ''
+
+    def _listdir(self, path):
+        return []
+
+    def __init__(self):
+        pass
+
+
+empty_provider = EmptyProvider()
+
+
+class ZipManifests(dict):
+    """
+    zip manifest builder
+    """
+
+    @classmethod
+    def build(cls, path):
+        """
+        Build a dictionary similar to the zipimport directory
+        caches, except instead of tuples, store ZipInfo objects.
+
+        Use a platform-specific path separator (os.sep) for the path keys
+        for compatibility with pypy on Windows.
+        """
+        with zipfile.ZipFile(path) as zfile:
+            items = (
+                (
+                    name.replace('/', os.sep),
+                    zfile.getinfo(name),
+                )
+                for name in zfile.namelist()
+            )
+            return dict(items)
+
+    load = build
+
+
+class MemoizedZipManifests(ZipManifests):
+    """
+    Memoized zipfile manifests.
+    """
+
+    manifest_mod = collections.namedtuple('manifest_mod', 'manifest mtime')
+
+    def load(self, path):
+        """
+        Load a manifest at path or return a suitable manifest already loaded.
+        """
+        path = os.path.normpath(path)
+        mtime = os.stat(path).st_mtime
+
+        if path not in self or self[path].mtime != mtime:
+            manifest = self.build(path)
+            self[path] = self.manifest_mod(manifest, mtime)
+
+        return self[path].manifest
+
+
+class ZipProvider(EggProvider):
+    """Resource support for zips and eggs"""
+
+    eagers = None
+    _zip_manifests = MemoizedZipManifests()
+
+    def __init__(self, module):
+        super().__init__(module)
+        self.zip_pre = self.loader.archive + os.sep
+
+    def _zipinfo_name(self, fspath):
+        # Convert a virtual filename (full path to file) into a zipfile subpath
+        # usable with the zipimport directory cache for our target archive
+        fspath = fspath.rstrip(os.sep)
+        if fspath == self.loader.archive:
+            return ''
+        if fspath.startswith(self.zip_pre):
+            return fspath[len(self.zip_pre) :]
+        raise AssertionError("%s is not a subpath of %s" % (fspath, self.zip_pre))
+
+    def _parts(self, zip_path):
+        # Convert a zipfile subpath into an egg-relative path part list.
+        # pseudo-fs path
+        fspath = self.zip_pre + zip_path
+        if fspath.startswith(self.egg_root + os.sep):
+            return fspath[len(self.egg_root) + 1 :].split(os.sep)
+        raise AssertionError("%s is not a subpath of %s" % (fspath, self.egg_root))
+
+    @property
+    def zipinfo(self):
+        return self._zip_manifests.load(self.loader.archive)
+
+    def get_resource_filename(self, manager, resource_name):
+        if not self.egg_name:
+            raise NotImplementedError(
+                "resource_filename() only supported for .egg, not .zip"
+            )
+        # no need to lock for extraction, since we use temp names
+        zip_path = self._resource_to_zip(resource_name)
+        eagers = self._get_eager_resources()
+        if '/'.join(self._parts(zip_path)) in eagers:
+            for name in eagers:
+                self._extract_resource(manager, self._eager_to_zip(name))
+        return self._extract_resource(manager, zip_path)
+
+    @staticmethod
+    def _get_date_and_size(zip_stat):
+        size = zip_stat.file_size
+        # ymdhms+wday, yday, dst
+        date_time = zip_stat.date_time + (0, 0, -1)
+        # 1980 offset already done
+        timestamp = time.mktime(date_time)
+        return timestamp, size
+
+    # FIXME: 'ZipProvider._extract_resource' is too complex (12)
+    def _extract_resource(self, manager, zip_path):  # noqa: C901
+        if zip_path in self._index():
+            for name in self._index()[zip_path]:
+                last = self._extract_resource(manager, os.path.join(zip_path, name))
+            # return the extracted directory name
+            return os.path.dirname(last)
+
+        timestamp, size = self._get_date_and_size(self.zipinfo[zip_path])
+
+        if not WRITE_SUPPORT:
+            raise IOError(
+                '"os.rename" and "os.unlink" are not supported ' 'on this platform'
+            )
+        try:
+            real_path = manager.get_cache_path(self.egg_name, self._parts(zip_path))
+
+            if self._is_current(real_path, zip_path):
+                return real_path
+
+            outf, tmpnam = _mkstemp(
+                ".$extract",
+                dir=os.path.dirname(real_path),
+            )
+            os.write(outf, self.loader.get_data(zip_path))
+            os.close(outf)
+            utime(tmpnam, (timestamp, timestamp))
+            manager.postprocess(tmpnam, real_path)
+
+            try:
+                rename(tmpnam, real_path)
+
+            except os.error:
+                if os.path.isfile(real_path):
+                    if self._is_current(real_path, zip_path):
+                        # the file became current since it was checked above,
+                        #  so proceed.
+                        return real_path
+                    # Windows, del old file and retry
+                    elif os.name == 'nt':
+                        unlink(real_path)
+                        rename(tmpnam, real_path)
+                        return real_path
+                raise
+
+        except os.error:
+            # report a user-friendly error
+            manager.extraction_error()
+
+        return real_path
+
+    def _is_current(self, file_path, zip_path):
+        """
+        Return True if the file_path is current for this zip_path
+        """
+        timestamp, size = self._get_date_and_size(self.zipinfo[zip_path])
+        if not os.path.isfile(file_path):
+            return False
+        stat = os.stat(file_path)
+        if stat.st_size != size or stat.st_mtime != timestamp:
+            return False
+        # check that the contents match
+        zip_contents = self.loader.get_data(zip_path)
+        with open(file_path, 'rb') as f:
+            file_contents = f.read()
+        return zip_contents == file_contents
+
+    def _get_eager_resources(self):
+        if self.eagers is None:
+            eagers = []
+            for name in ('native_libs.txt', 'eager_resources.txt'):
+                if self.has_metadata(name):
+                    eagers.extend(self.get_metadata_lines(name))
+            self.eagers = eagers
+        return self.eagers
+
+    def _index(self):
+        try:
+            return self._dirindex
+        except AttributeError:
+            ind = {}
+            for path in self.zipinfo:
+                parts = path.split(os.sep)
+                while parts:
+                    parent = os.sep.join(parts[:-1])
+                    if parent in ind:
+                        ind[parent].append(parts[-1])
+                        break
+                    else:
+                        ind[parent] = [parts.pop()]
+            self._dirindex = ind
+            return ind
+
+    def _has(self, fspath):
+        zip_path = self._zipinfo_name(fspath)
+        return zip_path in self.zipinfo or zip_path in self._index()
+
+    def _isdir(self, fspath):
+        return self._zipinfo_name(fspath) in self._index()
+
+    def _listdir(self, fspath):
+        return list(self._index().get(self._zipinfo_name(fspath), ()))
+
+    def _eager_to_zip(self, resource_name):
+        return self._zipinfo_name(self._fn(self.egg_root, resource_name))
+
+    def _resource_to_zip(self, resource_name):
+        return self._zipinfo_name(self._fn(self.module_path, resource_name))
+
+
+register_loader_type(zipimport.zipimporter, ZipProvider)
+
+
+class FileMetadata(EmptyProvider):
+    """Metadata handler for standalone PKG-INFO files
+
+    Usage::
+
+        metadata = FileMetadata("/path/to/PKG-INFO")
+
+    This provider rejects all data and metadata requests except for PKG-INFO,
+    which is treated as existing, and will be the contents of the file at
+    the provided location.
+    """
+
+    def __init__(self, path):
+        self.path = path
+
+    def _get_metadata_path(self, name):
+        return self.path
+
+    def has_metadata(self, name):
+        return name == 'PKG-INFO' and os.path.isfile(self.path)
+
+    def get_metadata(self, name):
+        if name != 'PKG-INFO':
+            raise KeyError("No metadata except PKG-INFO is available")
+
+        with io.open(self.path, encoding='utf-8', errors="replace") as f:
+            metadata = f.read()
+        self._warn_on_replacement(metadata)
+        return metadata
+
+    def _warn_on_replacement(self, metadata):
+        replacement_char = '�'
+        if replacement_char in metadata:
+            tmpl = "{self.path} could not be properly decoded in UTF-8"
+            msg = tmpl.format(**locals())
+            warnings.warn(msg)
+
+    def get_metadata_lines(self, name):
+        return yield_lines(self.get_metadata(name))
+
+
+class PathMetadata(DefaultProvider):
+    """Metadata provider for egg directories
+
+    Usage::
+
+        # Development eggs:
+
+        egg_info = "/path/to/PackageName.egg-info"
+        base_dir = os.path.dirname(egg_info)
+        metadata = PathMetadata(base_dir, egg_info)
+        dist_name = os.path.splitext(os.path.basename(egg_info))[0]
+        dist = Distribution(basedir, project_name=dist_name, metadata=metadata)
+
+        # Unpacked egg directories:
+
+        egg_path = "/path/to/PackageName-ver-pyver-etc.egg"
+        metadata = PathMetadata(egg_path, os.path.join(egg_path,'EGG-INFO'))
+        dist = Distribution.from_filename(egg_path, metadata=metadata)
+    """
+
+    def __init__(self, path, egg_info):
+        self.module_path = path
+        self.egg_info = egg_info
+
+
+class EggMetadata(ZipProvider):
+    """Metadata provider for .egg files"""
+
+    def __init__(self, importer):
+        """Create a metadata provider from a zipimporter"""
+
+        self.zip_pre = importer.archive + os.sep
+        self.loader = importer
+        if importer.prefix:
+            self.module_path = os.path.join(importer.archive, importer.prefix)
+        else:
+            self.module_path = importer.archive
+        self._setup_prefix()
+
+
+_declare_state('dict', _distribution_finders={})
+
+
+def register_finder(importer_type, distribution_finder):
+    """Register `distribution_finder` to find distributions in sys.path items
+
+    `importer_type` is the type or class of a PEP 302 "Importer" (sys.path item
+    handler), and `distribution_finder` is a callable that, passed a path
+    item and the importer instance, yields ``Distribution`` instances found on
+    that path item.  See ``pkg_resources.find_on_path`` for an example."""
+    _distribution_finders[importer_type] = distribution_finder
+
+
+def find_distributions(path_item, only=False):
+    """Yield distributions accessible via `path_item`"""
+    importer = get_importer(path_item)
+    finder = _find_adapter(_distribution_finders, importer)
+    return finder(importer, path_item, only)
+
+
+def find_eggs_in_zip(importer, path_item, only=False):
+    """
+    Find eggs in zip files; possibly multiple nested eggs.
+    """
+    if importer.archive.endswith('.whl'):
+        # wheels are not supported with this finder
+        # they don't have PKG-INFO metadata, and won't ever contain eggs
+        return
+    metadata = EggMetadata(importer)
+    if metadata.has_metadata('PKG-INFO'):
+        yield Distribution.from_filename(path_item, metadata=metadata)
+    if only:
+        # don't yield nested distros
+        return
+    for subitem in metadata.resource_listdir(''):
+        if _is_egg_path(subitem):
+            subpath = os.path.join(path_item, subitem)
+            dists = find_eggs_in_zip(zipimport.zipimporter(subpath), subpath)
+            for dist in dists:
+                yield dist
+        elif subitem.lower().endswith(('.dist-info', '.egg-info')):
+            subpath = os.path.join(path_item, subitem)
+            submeta = EggMetadata(zipimport.zipimporter(subpath))
+            submeta.egg_info = subpath
+            yield Distribution.from_location(path_item, subitem, submeta)
+
+
+register_finder(zipimport.zipimporter, find_eggs_in_zip)
+
+
+def find_nothing(importer, path_item, only=False):
+    return ()
+
+
+register_finder(object, find_nothing)
+
+
+def find_on_path(importer, path_item, only=False):
+    """Yield distributions accessible on a sys.path directory"""
+    path_item = _normalize_cached(path_item)
+
+    if _is_unpacked_egg(path_item):
+        yield Distribution.from_filename(
+            path_item,
+            metadata=PathMetadata(path_item, os.path.join(path_item, 'EGG-INFO')),
+        )
+        return
+
+    entries = (os.path.join(path_item, child) for child in safe_listdir(path_item))
+
+    # scan for .egg and .egg-info in directory
+    for entry in sorted(entries):
+        fullpath = os.path.join(path_item, entry)
+        factory = dist_factory(path_item, entry, only)
+        for dist in factory(fullpath):
+            yield dist
+
+
+def dist_factory(path_item, entry, only):
+    """Return a dist_factory for the given entry."""
+    lower = entry.lower()
+    is_egg_info = lower.endswith('.egg-info')
+    is_dist_info = lower.endswith('.dist-info') and os.path.isdir(
+        os.path.join(path_item, entry)
+    )
+    is_meta = is_egg_info or is_dist_info
+    return (
+        distributions_from_metadata
+        if is_meta
+        else find_distributions
+        if not only and _is_egg_path(entry)
+        else resolve_egg_link
+        if not only and lower.endswith('.egg-link')
+        else NoDists()
+    )
+
+
+class NoDists:
+    """
+    >>> bool(NoDists())
+    False
+
+    >>> list(NoDists()('anything'))
+    []
+    """
+
+    def __bool__(self):
+        return False
+
+    def __call__(self, fullpath):
+        return iter(())
+
+
+def safe_listdir(path):
+    """
+    Attempt to list contents of path, but suppress some exceptions.
+    """
+    try:
+        return os.listdir(path)
+    except (PermissionError, NotADirectoryError):
+        pass
+    except OSError as e:
+        # Ignore the directory if does not exist, not a directory or
+        # permission denied
+        if e.errno not in (errno.ENOTDIR, errno.EACCES, errno.ENOENT):
+            raise
+    return ()
+
+
+def distributions_from_metadata(path):
+    root = os.path.dirname(path)
+    if os.path.isdir(path):
+        if len(os.listdir(path)) == 0:
+            # empty metadata dir; skip
+            return
+        metadata = PathMetadata(root, path)
+    else:
+        metadata = FileMetadata(path)
+    entry = os.path.basename(path)
+    yield Distribution.from_location(
+        root,
+        entry,
+        metadata,
+        precedence=DEVELOP_DIST,
+    )
+
+
+def non_empty_lines(path):
+    """
+    Yield non-empty lines from file at path
+    """
+    with open(path) as f:
+        for line in f:
+            line = line.strip()
+            if line:
+                yield line
+
+
+def resolve_egg_link(path):
+    """
+    Given a path to an .egg-link, resolve distributions
+    present in the referenced path.
+    """
+    referenced_paths = non_empty_lines(path)
+    resolved_paths = (
+        os.path.join(os.path.dirname(path), ref) for ref in referenced_paths
+    )
+    dist_groups = map(find_distributions, resolved_paths)
+    return next(dist_groups, ())
+
+
+if hasattr(pkgutil, 'ImpImporter'):
+    register_finder(pkgutil.ImpImporter, find_on_path)
+
+register_finder(importlib_machinery.FileFinder, find_on_path)
+
+_declare_state('dict', _namespace_handlers={})
+_declare_state('dict', _namespace_packages={})
+
+
+def register_namespace_handler(importer_type, namespace_handler):
+    """Register `namespace_handler` to declare namespace packages
+
+    `importer_type` is the type or class of a PEP 302 "Importer" (sys.path item
+    handler), and `namespace_handler` is a callable like this::
+
+        def namespace_handler(importer, path_entry, moduleName, module):
+            # return a path_entry to use for child packages
+
+    Namespace handlers are only called if the importer object has already
+    agreed that it can handle the relevant path item, and they should only
+    return a subpath if the module __path__ does not already contain an
+    equivalent subpath.  For an example namespace handler, see
+    ``pkg_resources.file_ns_handler``.
+    """
+    _namespace_handlers[importer_type] = namespace_handler
+
+
+def _handle_ns(packageName, path_item):
+    """Ensure that named package includes a subpath of path_item (if needed)"""
+
+    importer = get_importer(path_item)
+    if importer is None:
+        return None
+
+    # use find_spec (PEP 451) and fall-back to find_module (PEP 302)
+    try:
+        spec = importer.find_spec(packageName)
+    except AttributeError:
+        # capture warnings due to #1111
+        with warnings.catch_warnings():
+            warnings.simplefilter("ignore")
+            loader = importer.find_module(packageName)
+    else:
+        loader = spec.loader if spec else None
+
+    if loader is None:
+        return None
+    module = sys.modules.get(packageName)
+    if module is None:
+        module = sys.modules[packageName] = types.ModuleType(packageName)
+        module.__path__ = []
+        _set_parent_ns(packageName)
+    elif not hasattr(module, '__path__'):
+        raise TypeError("Not a package:", packageName)
+    handler = _find_adapter(_namespace_handlers, importer)
+    subpath = handler(importer, path_item, packageName, module)
+    if subpath is not None:
+        path = module.__path__
+        path.append(subpath)
+        importlib.import_module(packageName)
+        _rebuild_mod_path(path, packageName, module)
+    return subpath
+
+
+def _rebuild_mod_path(orig_path, package_name, module):
+    """
+    Rebuild module.__path__ ensuring that all entries are ordered
+    corresponding to their sys.path order
+    """
+    sys_path = [_normalize_cached(p) for p in sys.path]
+
+    def safe_sys_path_index(entry):
+        """
+        Workaround for #520 and #513.
+        """
+        try:
+            return sys_path.index(entry)
+        except ValueError:
+            return float('inf')
+
+    def position_in_sys_path(path):
+        """
+        Return the ordinal of the path based on its position in sys.path
+        """
+        path_parts = path.split(os.sep)
+        module_parts = package_name.count('.') + 1
+        parts = path_parts[:-module_parts]
+        return safe_sys_path_index(_normalize_cached(os.sep.join(parts)))
+
+    new_path = sorted(orig_path, key=position_in_sys_path)
+    new_path = [_normalize_cached(p) for p in new_path]
+
+    if isinstance(module.__path__, list):
+        module.__path__[:] = new_path
+    else:
+        module.__path__ = new_path
+
+
+def declare_namespace(packageName):
+    """Declare that package 'packageName' is a namespace package"""
+
+    msg = (
+        f"Deprecated call to `pkg_resources.declare_namespace({packageName!r})`.\n"
+        "Implementing implicit namespace packages (as specified in PEP 420) "
+        "is preferred to `pkg_resources.declare_namespace`. "
+        "See https://setuptools.pypa.io/en/latest/references/"
+        "keywords.html#keyword-namespace-packages"
+    )
+    warnings.warn(msg, DeprecationWarning, stacklevel=2)
+
+    _imp.acquire_lock()
+    try:
+        if packageName in _namespace_packages:
+            return
+
+        path = sys.path
+        parent, _, _ = packageName.rpartition('.')
+
+        if parent:
+            declare_namespace(parent)
+            if parent not in _namespace_packages:
+                __import__(parent)
+            try:
+                path = sys.modules[parent].__path__
+            except AttributeError as e:
+                raise TypeError("Not a package:", parent) from e
+
+        # Track what packages are namespaces, so when new path items are added,
+        # they can be updated
+        _namespace_packages.setdefault(parent or None, []).append(packageName)
+        _namespace_packages.setdefault(packageName, [])
+
+        for path_item in path:
+            # Ensure all the parent's path items are reflected in the child,
+            # if they apply
+            _handle_ns(packageName, path_item)
+
+    finally:
+        _imp.release_lock()
+
+
+def fixup_namespace_packages(path_item, parent=None):
+    """Ensure that previously-declared namespace packages include path_item"""
+    _imp.acquire_lock()
+    try:
+        for package in _namespace_packages.get(parent, ()):
+            subpath = _handle_ns(package, path_item)
+            if subpath:
+                fixup_namespace_packages(subpath, package)
+    finally:
+        _imp.release_lock()
+
+
+def file_ns_handler(importer, path_item, packageName, module):
+    """Compute an ns-package subpath for a filesystem or zipfile importer"""
+
+    subpath = os.path.join(path_item, packageName.split('.')[-1])
+    normalized = _normalize_cached(subpath)
+    for item in module.__path__:
+        if _normalize_cached(item) == normalized:
+            break
+    else:
+        # Only return the path if it's not already there
+        return subpath
+
+
+if hasattr(pkgutil, 'ImpImporter'):
+    register_namespace_handler(pkgutil.ImpImporter, file_ns_handler)
+
+register_namespace_handler(zipimport.zipimporter, file_ns_handler)
+register_namespace_handler(importlib_machinery.FileFinder, file_ns_handler)
+
+
+def null_ns_handler(importer, path_item, packageName, module):
+    return None
+
+
+register_namespace_handler(object, null_ns_handler)
+
+
+def normalize_path(filename):
+    """Normalize a file/dir name for comparison purposes"""
+    return os.path.normcase(os.path.realpath(os.path.normpath(_cygwin_patch(filename))))
+
+
+def _cygwin_patch(filename):  # pragma: nocover
+    """
+    Contrary to POSIX 2008, on Cygwin, getcwd (3) contains
+    symlink components. Using
+    os.path.abspath() works around this limitation. A fix in os.getcwd()
+    would probably better, in Cygwin even more so, except
+    that this seems to be by design...
+    """
+    return os.path.abspath(filename) if sys.platform == 'cygwin' else filename
+
+
+def _normalize_cached(filename, _cache={}):
+    try:
+        return _cache[filename]
+    except KeyError:
+        _cache[filename] = result = normalize_path(filename)
+        return result
+
+
+def _is_egg_path(path):
+    """
+    Determine if given path appears to be an egg.
+    """
+    return _is_zip_egg(path) or _is_unpacked_egg(path)
+
+
+def _is_zip_egg(path):
+    return (
+        path.lower().endswith('.egg')
+        and os.path.isfile(path)
+        and zipfile.is_zipfile(path)
+    )
+
+
+def _is_unpacked_egg(path):
+    """
+    Determine if given path appears to be an unpacked egg.
+    """
+    return path.lower().endswith('.egg') and os.path.isfile(
+        os.path.join(path, 'EGG-INFO', 'PKG-INFO')
+    )
+
+
+def _set_parent_ns(packageName):
+    parts = packageName.split('.')
+    name = parts.pop()
+    if parts:
+        parent = '.'.join(parts)
+        setattr(sys.modules[parent], name, sys.modules[packageName])
+
+
+MODULE = re.compile(r"\w+(\.\w+)*$").match
+EGG_NAME = re.compile(
+    r"""
+    (?P<name>[^-]+) (
+        -(?P<ver>[^-]+) (
+            -py(?P<pyver>[^-]+) (
+                -(?P<plat>.+)
+            )?
+        )?
+    )?
+    """,
+    re.VERBOSE | re.IGNORECASE,
+).match
+
+
+class EntryPoint:
+    """Object representing an advertised importable object"""
+
+    def __init__(self, name, module_name, attrs=(), extras=(), dist=None):
+        if not MODULE(module_name):
+            raise ValueError("Invalid module name", module_name)
+        self.name = name
+        self.module_name = module_name
+        self.attrs = tuple(attrs)
+        self.extras = tuple(extras)
+        self.dist = dist
+
+    def __str__(self):
+        s = "%s = %s" % (self.name, self.module_name)
+        if self.attrs:
+            s += ':' + '.'.join(self.attrs)
+        if self.extras:
+            s += ' [%s]' % ','.join(self.extras)
+        return s
+
+    def __repr__(self):
+        return "EntryPoint.parse(%r)" % str(self)
+
+    def load(self, require=True, *args, **kwargs):
+        """
+        Require packages for this EntryPoint, then resolve it.
+        """
+        if not require or args or kwargs:
+            warnings.warn(
+                "Parameters to load are deprecated.  Call .resolve and "
+                ".require separately.",
+                PkgResourcesDeprecationWarning,
+                stacklevel=2,
+            )
+        if require:
+            self.require(*args, **kwargs)
+        return self.resolve()
+
+    def resolve(self):
+        """
+        Resolve the entry point from its module and attrs.
+        """
+        module = __import__(self.module_name, fromlist=['__name__'], level=0)
+        try:
+            return functools.reduce(getattr, self.attrs, module)
+        except AttributeError as exc:
+            raise ImportError(str(exc)) from exc
+
+    def require(self, env=None, installer=None):
+        if self.extras and not self.dist:
+            raise UnknownExtra("Can't require() without a distribution", self)
+
+        # Get the requirements for this entry point with all its extras and
+        # then resolve them. We have to pass `extras` along when resolving so
+        # that the working set knows what extras we want. Otherwise, for
+        # dist-info distributions, the working set will assume that the
+        # requirements for that extra are purely optional and skip over them.
+        reqs = self.dist.requires(self.extras)
+        items = working_set.resolve(reqs, env, installer, extras=self.extras)
+        list(map(working_set.add, items))
+
+    pattern = re.compile(
+        r'\s*'
+        r'(?P<name>.+?)\s*'
+        r'=\s*'
+        r'(?P<module>[\w.]+)\s*'
+        r'(:\s*(?P<attr>[\w.]+))?\s*'
+        r'(?P<extras>\[.*\])?\s*$'
+    )
+
+    @classmethod
+    def parse(cls, src, dist=None):
+        """Parse a single entry point from string `src`
+
+        Entry point syntax follows the form::
+
+            name = some.module:some.attr [extra1, extra2]
+
+        The entry name and module name are required, but the ``:attrs`` and
+        ``[extras]`` parts are optional
+        """
+        m = cls.pattern.match(src)
+        if not m:
+            msg = "EntryPoint must be in 'name=module:attrs [extras]' format"
+            raise ValueError(msg, src)
+        res = m.groupdict()
+        extras = cls._parse_extras(res['extras'])
+        attrs = res['attr'].split('.') if res['attr'] else ()
+        return cls(res['name'], res['module'], attrs, extras, dist)
+
+    @classmethod
+    def _parse_extras(cls, extras_spec):
+        if not extras_spec:
+            return ()
+        req = Requirement.parse('x' + extras_spec)
+        if req.specs:
+            raise ValueError()
+        return req.extras
+
+    @classmethod
+    def parse_group(cls, group, lines, dist=None):
+        """Parse an entry point group"""
+        if not MODULE(group):
+            raise ValueError("Invalid group name", group)
+        this = {}
+        for line in yield_lines(lines):
+            ep = cls.parse(line, dist)
+            if ep.name in this:
+                raise ValueError("Duplicate entry point", group, ep.name)
+            this[ep.name] = ep
+        return this
+
+    @classmethod
+    def parse_map(cls, data, dist=None):
+        """Parse a map of entry point groups"""
+        if isinstance(data, dict):
+            data = data.items()
+        else:
+            data = split_sections(data)
+        maps = {}
+        for group, lines in data:
+            if group is None:
+                if not lines:
+                    continue
+                raise ValueError("Entry points must be listed in groups")
+            group = group.strip()
+            if group in maps:
+                raise ValueError("Duplicate group name", group)
+            maps[group] = cls.parse_group(group, lines, dist)
+        return maps
+
+
+def _version_from_file(lines):
+    """
+    Given an iterable of lines from a Metadata file, return
+    the value of the Version field, if present, or None otherwise.
+    """
+
+    def is_version_line(line):
+        return line.lower().startswith('version:')
+
+    version_lines = filter(is_version_line, lines)
+    line = next(iter(version_lines), '')
+    _, _, value = line.partition(':')
+    return safe_version(value.strip()) or None
+
+
+class Distribution:
+    """Wrap an actual or potential sys.path entry w/metadata"""
+
+    PKG_INFO = 'PKG-INFO'
+
+    def __init__(
+        self,
+        location=None,
+        metadata=None,
+        project_name=None,
+        version=None,
+        py_version=PY_MAJOR,
+        platform=None,
+        precedence=EGG_DIST,
+    ):
+        self.project_name = safe_name(project_name or 'Unknown')
+        if version is not None:
+            self._version = safe_version(version)
+        self.py_version = py_version
+        self.platform = platform
+        self.location = location
+        self.precedence = precedence
+        self._provider = metadata or empty_provider
+
+    @classmethod
+    def from_location(cls, location, basename, metadata=None, **kw):
+        project_name, version, py_version, platform = [None] * 4
+        basename, ext = os.path.splitext(basename)
+        if ext.lower() in _distributionImpl:
+            cls = _distributionImpl[ext.lower()]
+
+            match = EGG_NAME(basename)
+            if match:
+                project_name, version, py_version, platform = match.group(
+                    'name', 'ver', 'pyver', 'plat'
+                )
+        return cls(
+            location,
+            metadata,
+            project_name=project_name,
+            version=version,
+            py_version=py_version,
+            platform=platform,
+            **kw,
+        )._reload_version()
+
+    def _reload_version(self):
+        return self
+
+    @property
+    def hashcmp(self):
+        return (
+            self._forgiving_parsed_version,
+            self.precedence,
+            self.key,
+            self.location,
+            self.py_version or '',
+            self.platform or '',
+        )
+
+    def __hash__(self):
+        return hash(self.hashcmp)
+
+    def __lt__(self, other):
+        return self.hashcmp < other.hashcmp
+
+    def __le__(self, other):
+        return self.hashcmp <= other.hashcmp
+
+    def __gt__(self, other):
+        return self.hashcmp > other.hashcmp
+
+    def __ge__(self, other):
+        return self.hashcmp >= other.hashcmp
+
+    def __eq__(self, other):
+        if not isinstance(other, self.__class__):
+            # It's not a Distribution, so they are not equal
+            return False
+        return self.hashcmp == other.hashcmp
+
+    def __ne__(self, other):
+        return not self == other
+
+    # These properties have to be lazy so that we don't have to load any
+    # metadata until/unless it's actually needed.  (i.e., some distributions
+    # may not know their name or version without loading PKG-INFO)
+
+    @property
+    def key(self):
+        try:
+            return self._key
+        except AttributeError:
+            self._key = key = self.project_name.lower()
+            return key
+
+    @property
+    def parsed_version(self):
+        if not hasattr(self, "_parsed_version"):
+            try:
+                self._parsed_version = parse_version(self.version)
+            except packaging.version.InvalidVersion as ex:
+                info = f"(package: {self.project_name})"
+                if hasattr(ex, "add_note"):
+                    ex.add_note(info)  # PEP 678
+                    raise
+                raise packaging.version.InvalidVersion(f"{str(ex)} {info}") from None
+
+        return self._parsed_version
+
+    @property
+    def _forgiving_parsed_version(self):
+        try:
+            return self.parsed_version
+        except packaging.version.InvalidVersion as ex:
+            self._parsed_version = parse_version(_forgiving_version(self.version))
+
+            notes = "\n".join(getattr(ex, "__notes__", []))  # PEP 678
+            msg = f"""!!\n\n
+            *************************************************************************
+            {str(ex)}\n{notes}
+
+            This is a long overdue deprecation.
+            For the time being, `pkg_resources` will use `{self._parsed_version}`
+            as a replacement to avoid breaking existing environments,
+            but no future compatibility is guaranteed.
+
+            If you maintain package {self.project_name} you should implement
+            the relevant changes to adequate the project to PEP 440 immediately.
+            *************************************************************************
+            \n\n!!
+            """
+            warnings.warn(msg, DeprecationWarning)
+
+            return self._parsed_version
+
+    @property
+    def version(self):
+        try:
+            return self._version
+        except AttributeError as e:
+            version = self._get_version()
+            if version is None:
+                path = self._get_metadata_path_for_display(self.PKG_INFO)
+                msg = ("Missing 'Version:' header and/or {} file at path: {}").format(
+                    self.PKG_INFO, path
+                )
+                raise ValueError(msg, self) from e
+
+            return version
+
+    @property
+    def _dep_map(self):
+        """
+        A map of extra to its list of (direct) requirements
+        for this distribution, including the null extra.
+        """
+        try:
+            return self.__dep_map
+        except AttributeError:
+            self.__dep_map = self._filter_extras(self._build_dep_map())
+        return self.__dep_map
+
+    @staticmethod
+    def _filter_extras(dm):
+        """
+        Given a mapping of extras to dependencies, strip off
+        environment markers and filter out any dependencies
+        not matching the markers.
+        """
+        for extra in list(filter(None, dm)):
+            new_extra = extra
+            reqs = dm.pop(extra)
+            new_extra, _, marker = extra.partition(':')
+            fails_marker = marker and (
+                invalid_marker(marker) or not evaluate_marker(marker)
+            )
+            if fails_marker:
+                reqs = []
+            new_extra = safe_extra(new_extra) or None
+
+            dm.setdefault(new_extra, []).extend(reqs)
+        return dm
+
+    def _build_dep_map(self):
+        dm = {}
+        for name in 'requires.txt', 'depends.txt':
+            for extra, reqs in split_sections(self._get_metadata(name)):
+                dm.setdefault(extra, []).extend(parse_requirements(reqs))
+        return dm
+
+    def requires(self, extras=()):
+        """List of Requirements needed for this distro if `extras` are used"""
+        dm = self._dep_map
+        deps = []
+        deps.extend(dm.get(None, ()))
+        for ext in extras:
+            try:
+                deps.extend(dm[safe_extra(ext)])
+            except KeyError as e:
+                raise UnknownExtra(
+                    "%s has no such extra feature %r" % (self, ext)
+                ) from e
+        return deps
+
+    def _get_metadata_path_for_display(self, name):
+        """
+        Return the path to the given metadata file, if available.
+        """
+        try:
+            # We need to access _get_metadata_path() on the provider object
+            # directly rather than through this class's __getattr__()
+            # since _get_metadata_path() is marked private.
+            path = self._provider._get_metadata_path(name)
+
+        # Handle exceptions e.g. in case the distribution's metadata
+        # provider doesn't support _get_metadata_path().
+        except Exception:
+            return '[could not detect]'
+
+        return path
+
+    def _get_metadata(self, name):
+        if self.has_metadata(name):
+            for line in self.get_metadata_lines(name):
+                yield line
+
+    def _get_version(self):
+        lines = self._get_metadata(self.PKG_INFO)
+        version = _version_from_file(lines)
+
+        return version
+
+    def activate(self, path=None, replace=False):
+        """Ensure distribution is importable on `path` (default=sys.path)"""
+        if path is None:
+            path = sys.path
+        self.insert_on(path, replace=replace)
+        if path is sys.path:
+            fixup_namespace_packages(self.location)
+            for pkg in self._get_metadata('namespace_packages.txt'):
+                if pkg in sys.modules:
+                    declare_namespace(pkg)
+
+    def egg_name(self):
+        """Return what this distribution's standard .egg filename should be"""
+        filename = "%s-%s-py%s" % (
+            to_filename(self.project_name),
+            to_filename(self.version),
+            self.py_version or PY_MAJOR,
+        )
+
+        if self.platform:
+            filename += '-' + self.platform
+        return filename
+
+    def __repr__(self):
+        if self.location:
+            return "%s (%s)" % (self, self.location)
+        else:
+            return str(self)
+
+    def __str__(self):
+        try:
+            version = getattr(self, 'version', None)
+        except ValueError:
+            version = None
+        version = version or "[unknown version]"
+        return "%s %s" % (self.project_name, version)
+
+    def __getattr__(self, attr):
+        """Delegate all unrecognized public attributes to .metadata provider"""
+        if attr.startswith('_'):
+            raise AttributeError(attr)
+        return getattr(self._provider, attr)
+
+    def __dir__(self):
+        return list(
+            set(super(Distribution, self).__dir__())
+            | set(attr for attr in self._provider.__dir__() if not attr.startswith('_'))
+        )
+
+    @classmethod
+    def from_filename(cls, filename, metadata=None, **kw):
+        return cls.from_location(
+            _normalize_cached(filename), os.path.basename(filename), metadata, **kw
+        )
+
+    def as_requirement(self):
+        """Return a ``Requirement`` that matches this distribution exactly"""
+        if isinstance(self.parsed_version, packaging.version.Version):
+            spec = "%s==%s" % (self.project_name, self.parsed_version)
+        else:
+            spec = "%s===%s" % (self.project_name, self.parsed_version)
+
+        return Requirement.parse(spec)
+
+    def load_entry_point(self, group, name):
+        """Return the `name` entry point of `group` or raise ImportError"""
+        ep = self.get_entry_info(group, name)
+        if ep is None:
+            raise ImportError("Entry point %r not found" % ((group, name),))
+        return ep.load()
+
+    def get_entry_map(self, group=None):
+        """Return the entry point map for `group`, or the full entry map"""
+        try:
+            ep_map = self._ep_map
+        except AttributeError:
+            ep_map = self._ep_map = EntryPoint.parse_map(
+                self._get_metadata('entry_points.txt'), self
+            )
+        if group is not None:
+            return ep_map.get(group, {})
+        return ep_map
+
+    def get_entry_info(self, group, name):
+        """Return the EntryPoint object for `group`+`name`, or ``None``"""
+        return self.get_entry_map(group).get(name)
+
+    # FIXME: 'Distribution.insert_on' is too complex (13)
+    def insert_on(self, path, loc=None, replace=False):  # noqa: C901
+        """Ensure self.location is on path
+
+        If replace=False (default):
+            - If location is already in path anywhere, do nothing.
+            - Else:
+              - If it's an egg and its parent directory is on path,
+                insert just ahead of the parent.
+              - Else: add to the end of path.
+        If replace=True:
+            - If location is already on path anywhere (not eggs)
+              or higher priority than its parent (eggs)
+              do nothing.
+            - Else:
+              - If it's an egg and its parent directory is on path,
+                insert just ahead of the parent,
+                removing any lower-priority entries.
+              - Else: add it to the front of path.
+        """
+
+        loc = loc or self.location
+        if not loc:
+            return
+
+        nloc = _normalize_cached(loc)
+        bdir = os.path.dirname(nloc)
+        npath = [(p and _normalize_cached(p) or p) for p in path]
+
+        for p, item in enumerate(npath):
+            if item == nloc:
+                if replace:
+                    break
+                else:
+                    # don't modify path (even removing duplicates) if
+                    # found and not replace
+                    return
+            elif item == bdir and self.precedence == EGG_DIST:
+                # if it's an .egg, give it precedence over its directory
+                # UNLESS it's already been added to sys.path and replace=False
+                if (not replace) and nloc in npath[p:]:
+                    return
+                if path is sys.path:
+                    self.check_version_conflict()
+                path.insert(p, loc)
+                npath.insert(p, nloc)
+                break
+        else:
+            if path is sys.path:
+                self.check_version_conflict()
+            if replace:
+                path.insert(0, loc)
+            else:
+                path.append(loc)
+            return
+
+        # p is the spot where we found or inserted loc; now remove duplicates
+        while True:
+            try:
+                np = npath.index(nloc, p + 1)
+            except ValueError:
+                break
+            else:
+                del npath[np], path[np]
+                # ha!
+                p = np
+
+        return
+
+    def check_version_conflict(self):
+        if self.key == 'setuptools':
+            # ignore the inevitable setuptools self-conflicts  :(
+            return
+
+        nsp = dict.fromkeys(self._get_metadata('namespace_packages.txt'))
+        loc = normalize_path(self.location)
+        for modname in self._get_metadata('top_level.txt'):
+            if (
+                modname not in sys.modules
+                or modname in nsp
+                or modname in _namespace_packages
+            ):
+                continue
+            if modname in ('pkg_resources', 'setuptools', 'site'):
+                continue
+            fn = getattr(sys.modules[modname], '__file__', None)
+            if fn and (
+                normalize_path(fn).startswith(loc) or fn.startswith(self.location)
+            ):
+                continue
+            issue_warning(
+                "Module %s was already imported from %s, but %s is being added"
+                " to sys.path" % (modname, fn, self.location),
+            )
+
+    def has_version(self):
+        try:
+            self.version
+        except ValueError:
+            issue_warning("Unbuilt egg for " + repr(self))
+            return False
+        except SystemError:
+            # TODO: remove this except clause when python/cpython#103632 is fixed.
+            return False
+        return True
+
+    def clone(self, **kw):
+        """Copy this distribution, substituting in any changed keyword args"""
+        names = 'project_name version py_version platform location precedence'
+        for attr in names.split():
+            kw.setdefault(attr, getattr(self, attr, None))
+        kw.setdefault('metadata', self._provider)
+        return self.__class__(**kw)
+
+    @property
+    def extras(self):
+        return [dep for dep in self._dep_map if dep]
+
+
+class EggInfoDistribution(Distribution):
+    def _reload_version(self):
+        """
+        Packages installed by distutils (e.g. numpy or scipy),
+        which uses an old safe_version, and so
+        their version numbers can get mangled when
+        converted to filenames (e.g., 1.11.0.dev0+2329eae to
+        1.11.0.dev0_2329eae). These distributions will not be
+        parsed properly
+        downstream by Distribution and safe_version, so
+        take an extra step and try to get the version number from
+        the metadata file itself instead of the filename.
+        """
+        md_version = self._get_version()
+        if md_version:
+            self._version = md_version
+        return self
+
+
+class DistInfoDistribution(Distribution):
+    """
+    Wrap an actual or potential sys.path entry
+    w/metadata, .dist-info style.
+    """
+
+    PKG_INFO = 'METADATA'
+    EQEQ = re.compile(r"([\(,])\s*(\d.*?)\s*([,\)])")
+
+    @property
+    def _parsed_pkg_info(self):
+        """Parse and cache metadata"""
+        try:
+            return self._pkg_info
+        except AttributeError:
+            metadata = self.get_metadata(self.PKG_INFO)
+            self._pkg_info = email.parser.Parser().parsestr(metadata)
+            return self._pkg_info
+
+    @property
+    def _dep_map(self):
+        try:
+            return self.__dep_map
+        except AttributeError:
+            self.__dep_map = self._compute_dependencies()
+            return self.__dep_map
+
+    def _compute_dependencies(self):
+        """Recompute this distribution's dependencies."""
+        dm = self.__dep_map = {None: []}
+
+        reqs = []
+        # Including any condition expressions
+        for req in self._parsed_pkg_info.get_all('Requires-Dist') or []:
+            reqs.extend(parse_requirements(req))
+
+        def reqs_for_extra(extra):
+            for req in reqs:
+                if not req.marker or req.marker.evaluate({'extra': extra}):
+                    yield req
+
+        common = types.MappingProxyType(dict.fromkeys(reqs_for_extra(None)))
+        dm[None].extend(common)
+
+        for extra in self._parsed_pkg_info.get_all('Provides-Extra') or []:
+            s_extra = safe_extra(extra.strip())
+            dm[s_extra] = [r for r in reqs_for_extra(extra) if r not in common]
+
+        return dm
+
+
+_distributionImpl = {
+    '.egg': Distribution,
+    '.egg-info': EggInfoDistribution,
+    '.dist-info': DistInfoDistribution,
+}
+
+
+def issue_warning(*args, **kw):
+    level = 1
+    g = globals()
+    try:
+        # find the first stack frame that is *not* code in
+        # the pkg_resources module, to use for the warning
+        while sys._getframe(level).f_globals is g:
+            level += 1
+    except ValueError:
+        pass
+    warnings.warn(stacklevel=level + 1, *args, **kw)
+
+
+def parse_requirements(strs):
+    """
+    Yield ``Requirement`` objects for each specification in `strs`.
+
+    `strs` must be a string, or a (possibly-nested) iterable thereof.
+    """
+    return map(Requirement, join_continuation(map(drop_comment, yield_lines(strs))))
+
+
+class RequirementParseError(packaging.requirements.InvalidRequirement):
+    "Compatibility wrapper for InvalidRequirement"
+
+
+class Requirement(packaging.requirements.Requirement):
+    def __init__(self, requirement_string):
+        """DO NOT CALL THIS UNDOCUMENTED METHOD; use Requirement.parse()!"""
+        super(Requirement, self).__init__(requirement_string)
+        self.unsafe_name = self.name
+        project_name = safe_name(self.name)
+        self.project_name, self.key = project_name, project_name.lower()
+        self.specs = [(spec.operator, spec.version) for spec in self.specifier]
+        self.extras = tuple(map(safe_extra, self.extras))
+        self.hashCmp = (
+            self.key,
+            self.url,
+            self.specifier,
+            frozenset(self.extras),
+            str(self.marker) if self.marker else None,
+        )
+        self.__hash = hash(self.hashCmp)
+
+    def __eq__(self, other):
+        return isinstance(other, Requirement) and self.hashCmp == other.hashCmp
+
+    def __ne__(self, other):
+        return not self == other
+
+    def __contains__(self, item):
+        if isinstance(item, Distribution):
+            if item.key != self.key:
+                return False
+
+            item = item.version
+
+        # Allow prereleases always in order to match the previous behavior of
+        # this method. In the future this should be smarter and follow PEP 440
+        # more accurately.
+        return self.specifier.contains(item, prereleases=True)
+
+    def __hash__(self):
+        return self.__hash
+
+    def __repr__(self):
+        return "Requirement.parse(%r)" % str(self)
+
+    @staticmethod
+    def parse(s):
+        (req,) = parse_requirements(s)
+        return req
+
+
+def _always_object(classes):
+    """
+    Ensure object appears in the mro even
+    for old-style classes.
+    """
+    if object not in classes:
+        return classes + (object,)
+    return classes
+
+
+def _find_adapter(registry, ob):
+    """Return an adapter factory for `ob` from `registry`"""
+    types = _always_object(inspect.getmro(getattr(ob, '__class__', type(ob))))
+    for t in types:
+        if t in registry:
+            return registry[t]
+
+
+def ensure_directory(path):
+    """Ensure that the parent directory of `path` exists"""
+    dirname = os.path.dirname(path)
+    os.makedirs(dirname, exist_ok=True)
+
+
+def _bypass_ensure_directory(path):
+    """Sandbox-bypassing version of ensure_directory()"""
+    if not WRITE_SUPPORT:
+        raise IOError('"os.mkdir" not supported on this platform.')
+    dirname, filename = split(path)
+    if dirname and filename and not isdir(dirname):
+        _bypass_ensure_directory(dirname)
+        try:
+            mkdir(dirname, 0o755)
+        except FileExistsError:
+            pass
+
+
+def split_sections(s):
+    """Split a string or iterable thereof into (section, content) pairs
+
+    Each ``section`` is a stripped version of the section header ("[section]")
+    and each ``content`` is a list of stripped lines excluding blank lines and
+    comment-only lines.  If there are any such lines before the first section
+    header, they're returned in a first ``section`` of ``None``.
+    """
+    section = None
+    content = []
+    for line in yield_lines(s):
+        if line.startswith("["):
+            if line.endswith("]"):
+                if section or content:
+                    yield section, content
+                section = line[1:-1].strip()
+                content = []
+            else:
+                raise ValueError("Invalid section heading", line)
+        else:
+            content.append(line)
+
+    # wrap up last segment
+    yield section, content
+
+
+def _mkstemp(*args, **kw):
+    old_open = os.open
+    try:
+        # temporarily bypass sandboxing
+        os.open = os_open
+        return tempfile.mkstemp(*args, **kw)
+    finally:
+        # and then put it back
+        os.open = old_open
+
+
+# Silence the PEP440Warning by default, so that end users don't get hit by it
+# randomly just because they use pkg_resources. We want to append the rule
+# because we want earlier uses of filterwarnings to take precedence over this
+# one.
+warnings.filterwarnings("ignore", category=PEP440Warning, append=True)
+
+
+# from jaraco.functools 1.3
+def _call_aside(f, *args, **kwargs):
+    f(*args, **kwargs)
+    return f
+
+
+@_call_aside
+def _initialize(g=globals()):
+    "Set up global resource manager (deliberately not state-saved)"
+    manager = ResourceManager()
+    g['_manager'] = manager
+    g.update(
+        (name, getattr(manager, name))
+        for name in dir(manager)
+        if not name.startswith('_')
+    )
+
+
+class PkgResourcesDeprecationWarning(Warning):
+    """
+    Base class for warning about deprecations in ``pkg_resources``
+
+    This class is not derived from ``DeprecationWarning``, and as such is
+    visible by default.
+    """
+
+
+@_call_aside
+def _initialize_master_working_set():
+    """
+    Prepare the master working set and make the ``require()``
+    API available.
+
+    This function has explicit effects on the global state
+    of pkg_resources. It is intended to be invoked once at
+    the initialization of this module.
+
+    Invocation by other packages is unsupported and done
+    at their own risk.
+    """
+    working_set = WorkingSet._build_master()
+    _declare_state('object', working_set=working_set)
+
+    require = working_set.require
+    iter_entry_points = working_set.iter_entry_points
+    add_activation_listener = working_set.subscribe
+    run_script = working_set.run_script
+    # backward compatibility
+    run_main = run_script
+    # Activate all distributions already on sys.path with replace=False and
+    # ensure that all distributions added to the working set in the future
+    # (e.g. by calling ``require()``) will get activated as well,
+    # with higher priority (replace=True).
+    tuple(dist.activate(replace=False) for dist in working_set)
+    add_activation_listener(
+        lambda dist: dist.activate(replace=True),
+        existing=False,
+    )
+    working_set.entries = []
+    # match order
+    list(map(working_set.add_entry, sys.path))
+    globals().update(locals())
diff --git a/third_party/python/setuptools/pkg_resources/_vendor/__init__.py b/third_party/python/setuptools/pkg_resources/_vendor/__init__.py
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/third_party/python/setuptools/pkg_resources/_vendor/__init__.py
diff --git a/third_party/python/setuptools/pkg_resources/_vendor/importlib_resources/__init__.py b/third_party/python/setuptools/pkg_resources/_vendor/importlib_resources/__init__.py
new file mode 100644
index 0000000000..34e3a9950c
--- /dev/null
+++ b/third_party/python/setuptools/pkg_resources/_vendor/importlib_resources/__init__.py
@@ -0,0 +1,36 @@
+"""Read resources contained within a package."""
+
+from ._common import (
+    as_file,
+    files,
+    Package,
+)
+
+from ._legacy import (
+    contents,
+    open_binary,
+    read_binary,
+    open_text,
+    read_text,
+    is_resource,
+    path,
+    Resource,
+)
+
+from .abc import ResourceReader
+
+
+__all__ = [
+    'Package',
+    'Resource',
+    'ResourceReader',
+    'as_file',
+    'contents',
+    'files',
+    'is_resource',
+    'open_binary',
+    'open_text',
+    'path',
+    'read_binary',
+    'read_text',
+]
diff --git a/third_party/python/setuptools/pkg_resources/_vendor/importlib_resources/_adapters.py b/third_party/python/setuptools/pkg_resources/_vendor/importlib_resources/_adapters.py
new file mode 100644
index 0000000000..ea363d86a5
--- /dev/null
+++ b/third_party/python/setuptools/pkg_resources/_vendor/importlib_resources/_adapters.py
@@ -0,0 +1,170 @@
+from contextlib import suppress
+from io import TextIOWrapper
+
+from . import abc
+
+
+class SpecLoaderAdapter:
+    """
+    Adapt a package spec to adapt the underlying loader.
+    """
+
+    def __init__(self, spec, adapter=lambda spec: spec.loader):
+        self.spec = spec
+        self.loader = adapter(spec)
+
+    def __getattr__(self, name):
+        return getattr(self.spec, name)
+
+
+class TraversableResourcesLoader:
+    """
+    Adapt a loader to provide TraversableResources.
+    """
+
+    def __init__(self, spec):
+        self.spec = spec
+
+    def get_resource_reader(self, name):
+        return CompatibilityFiles(self.spec)._native()
+
+
+def _io_wrapper(file, mode='r', *args, **kwargs):
+    if mode == 'r':
+        return TextIOWrapper(file, *args, **kwargs)
+    elif mode == 'rb':
+        return file
+    raise ValueError(
+        "Invalid mode value '{}', only 'r' and 'rb' are supported".format(mode)
+    )
+
+
+class CompatibilityFiles:
+    """
+    Adapter for an existing or non-existent resource reader
+    to provide a compatibility .files().
+    """
+
+    class SpecPath(abc.Traversable):
+        """
+        Path tied to a module spec.
+        Can be read and exposes the resource reader children.
+        """
+
+        def __init__(self, spec, reader):
+            self._spec = spec
+            self._reader = reader
+
+        def iterdir(self):
+            if not self._reader:
+                return iter(())
+            return iter(
+                CompatibilityFiles.ChildPath(self._reader, path)
+                for path in self._reader.contents()
+            )
+
+        def is_file(self):
+            return False
+
+        is_dir = is_file
+
+        def joinpath(self, other):
+            if not self._reader:
+                return CompatibilityFiles.OrphanPath(other)
+            return CompatibilityFiles.ChildPath(self._reader, other)
+
+        @property
+        def name(self):
+            return self._spec.name
+
+        def open(self, mode='r', *args, **kwargs):
+            return _io_wrapper(self._reader.open_resource(None), mode, *args, **kwargs)
+
+    class ChildPath(abc.Traversable):
+        """
+        Path tied to a resource reader child.
+        Can be read but doesn't expose any meaningful children.
+        """
+
+        def __init__(self, reader, name):
+            self._reader = reader
+            self._name = name
+
+        def iterdir(self):
+            return iter(())
+
+        def is_file(self):
+            return self._reader.is_resource(self.name)
+
+        def is_dir(self):
+            return not self.is_file()
+
+        def joinpath(self, other):
+            return CompatibilityFiles.OrphanPath(self.name, other)
+
+        @property
+        def name(self):
+            return self._name
+
+        def open(self, mode='r', *args, **kwargs):
+            return _io_wrapper(
+                self._reader.open_resource(self.name), mode, *args, **kwargs
+            )
+
+    class OrphanPath(abc.Traversable):
+        """
+        Orphan path, not tied to a module spec or resource reader.
+        Can't be read and doesn't expose any meaningful children.
+        """
+
+        def __init__(self, *path_parts):
+            if len(path_parts) < 1:
+                raise ValueError('Need at least one path part to construct a path')
+            self._path = path_parts
+
+        def iterdir(self):
+            return iter(())
+
+        def is_file(self):
+            return False
+
+        is_dir = is_file
+
+        def joinpath(self, other):
+            return CompatibilityFiles.OrphanPath(*self._path, other)
+
+        @property
+        def name(self):
+            return self._path[-1]
+
+        def open(self, mode='r', *args, **kwargs):
+            raise FileNotFoundError("Can't open orphan path")
+
+    def __init__(self, spec):
+        self.spec = spec
+
+    @property
+    def _reader(self):
+        with suppress(AttributeError):
+            return self.spec.loader.get_resource_reader(self.spec.name)
+
+    def _native(self):
+        """
+        Return the native reader if it supports files().
+        """
+        reader = self._reader
+        return reader if hasattr(reader, 'files') else self
+
+    def __getattr__(self, attr):
+        return getattr(self._reader, attr)
+
+    def files(self):
+        return CompatibilityFiles.SpecPath(self.spec, self._reader)
+
+
+def wrap_spec(package):
+    """
+    Construct a package spec with traversable compatibility
+    on the spec/loader/reader.
+    """
+    return SpecLoaderAdapter(package.__spec__, TraversableResourcesLoader)
diff --git a/third_party/python/setuptools/pkg_resources/_vendor/importlib_resources/_common.py b/third_party/python/setuptools/pkg_resources/_vendor/importlib_resources/_common.py
new file mode 100644
index 0000000000..3c6de1cfb2
--- /dev/null
+++ b/third_party/python/setuptools/pkg_resources/_vendor/importlib_resources/_common.py
@@ -0,0 +1,207 @@
+import os
+import pathlib
+import tempfile
+import functools
+import contextlib
+import types
+import importlib
+import inspect
+import warnings
+import itertools
+
+from typing import Union, Optional, cast
+from .abc import ResourceReader, Traversable
+
+from ._compat import wrap_spec
+
+Package = Union[types.ModuleType, str]
+Anchor = Package
+
+
+def package_to_anchor(func):
+    """
+    Replace 'package' parameter as 'anchor' and warn about the change.
+
+    Other errors should fall through.
+
+    >>> files('a', 'b')
+    Traceback (most recent call last):
+    TypeError: files() takes from 0 to 1 positional arguments but 2 were given
+    """
+    undefined = object()
+
+    @functools.wraps(func)
+    def wrapper(anchor=undefined, package=undefined):
+        if package is not undefined:
+            if anchor is not undefined:
+                return func(anchor, package)
+            warnings.warn(
+                "First parameter to files is renamed to 'anchor'",
+                DeprecationWarning,
+                stacklevel=2,
+            )
+            return func(package)
+        elif anchor is undefined:
+            return func()
+        return func(anchor)
+
+    return wrapper
+
+
+@package_to_anchor
+def files(anchor: Optional[Anchor] = None) -> Traversable:
+    """
+    Get a Traversable resource for an anchor.
+    """
+    return from_package(resolve(anchor))
+
+
+def get_resource_reader(package: types.ModuleType) -> Optional[ResourceReader]:
+    """
+    Return the package's loader if it's a ResourceReader.
+    """
+    # We can't use
+    # a issubclass() check here because apparently abc.'s __subclasscheck__()
+    # hook wants to create a weak reference to the object, but
+    # zipimport.zipimporter does not support weak references, resulting in a
+    # TypeError.  That seems terrible.
+    spec = package.__spec__
+    reader = getattr(spec.loader, 'get_resource_reader', None)  # type: ignore
+    if reader is None:
+        return None
+    return reader(spec.name)  # type: ignore
+
+
+@functools.singledispatch
+def resolve(cand: Optional[Anchor]) -> types.ModuleType:
+    return cast(types.ModuleType, cand)
+
+
+@resolve.register
+def _(cand: str) -> types.ModuleType:
+    return importlib.import_module(cand)
+
+
+@resolve.register
+def _(cand: None) -> types.ModuleType:
+    return resolve(_infer_caller().f_globals['__name__'])
+
+
+def _infer_caller():
+    """
+    Walk the stack and find the frame of the first caller not in this module.
+    """
+
+    def is_this_file(frame_info):
+        return frame_info.filename == __file__
+
+    def is_wrapper(frame_info):
+        return frame_info.function == 'wrapper'
+
+    not_this_file = itertools.filterfalse(is_this_file, inspect.stack())
+    # also exclude 'wrapper' due to singledispatch in the call stack
+    callers = itertools.filterfalse(is_wrapper, not_this_file)
+    return next(callers).frame
+
+
+def from_package(package: types.ModuleType):
+    """
+    Return a Traversable object for the given package.
+
+    """
+    spec = wrap_spec(package)
+    reader = spec.loader.get_resource_reader(spec.name)
+    return reader.files()
+
+
+@contextlib.contextmanager
+def _tempfile(
+    reader,
+    suffix='',
+    # gh-93353: Keep a reference to call os.remove() in late Python
+    # finalization.
+    *,
+    _os_remove=os.remove,
+):
+    # Not using tempfile.NamedTemporaryFile as it leads to deeper 'try'
+    # blocks due to the need to close the temporary file to work on Windows
+    # properly.
+    fd, raw_path = tempfile.mkstemp(suffix=suffix)
+    try:
+        try:
+            os.write(fd, reader())
+        finally:
+            os.close(fd)
+        del reader
+        yield pathlib.Path(raw_path)
+    finally:
+        try:
+            _os_remove(raw_path)
+        except FileNotFoundError:
+            pass
+
+
+def _temp_file(path):
+    return _tempfile(path.read_bytes, suffix=path.name)
+
+
+def _is_present_dir(path: Traversable) -> bool:
+    """
+    Some Traversables implement ``is_dir()`` to raise an
+    exception (i.e. ``FileNotFoundError``) when the
+    directory doesn't exist. This function wraps that call
+    to always return a boolean and only return True
+    if there's a dir and it exists.
+    """
+    with contextlib.suppress(FileNotFoundError):
+        return path.is_dir()
+    return False
+
+
+@functools.singledispatch
+def as_file(path):
+    """
+    Given a Traversable object, return that object as a
+    path on the local file system in a context manager.
+    """
+    return _temp_dir(path) if _is_present_dir(path) else _temp_file(path)
+
+
+@as_file.register(pathlib.Path)
+@contextlib.contextmanager
+def _(path):
+    """
+    Degenerate behavior for pathlib.Path objects.
+    """
+    yield path
+
+
+@contextlib.contextmanager
+def _temp_path(dir: tempfile.TemporaryDirectory):
+    """
+    Wrap tempfile.TemporyDirectory to return a pathlib object.
+    """
+    with dir as result:
+        yield pathlib.Path(result)
+
+
+@contextlib.contextmanager
+def _temp_dir(path):
+    """
+    Given a traversable dir, recursively replicate the whole tree
+    to the file system in a context manager.
+    """
+    assert path.is_dir()
+    with _temp_path(tempfile.TemporaryDirectory()) as temp_dir:
+        yield _write_contents(temp_dir, path)
+
+
+def _write_contents(target, source):
+    child = target.joinpath(source.name)
+    if source.is_dir():
+        child.mkdir()
+        for item in source.iterdir():
+            _write_contents(child, item)
+    else:
+        child.write_bytes(source.read_bytes())
+    return child
diff --git a/third_party/python/setuptools/pkg_resources/_vendor/importlib_resources/_compat.py b/third_party/python/setuptools/pkg_resources/_vendor/importlib_resources/_compat.py
new file mode 100644
index 0000000000..8b5b1d280f
--- /dev/null
+++ b/third_party/python/setuptools/pkg_resources/_vendor/importlib_resources/_compat.py
@@ -0,0 +1,108 @@
+# flake8: noqa
+
+import abc
+import os
+import sys
+import pathlib
+from contextlib import suppress
+from typing import Union
+
+
+if sys.version_info >= (3, 10):
+    from zipfile import Path as ZipPath  # type: ignore
+else:
+    from ..zipp import Path as ZipPath  # type: ignore
+
+
+try:
+    from typing import runtime_checkable  # type: ignore
+except ImportError:
+
+    def runtime_checkable(cls):  # type: ignore
+        return cls
+
+
+try:
+    from typing import Protocol  # type: ignore
+except ImportError:
+    Protocol = abc.ABC  # type: ignore
+
+
+class TraversableResourcesLoader:
+    """
+    Adapt loaders to provide TraversableResources and other
+    compatibility.
+
+    Used primarily for Python 3.9 and earlier where the native
+    loaders do not yet implement TraversableResources.
+    """
+
+    def __init__(self, spec):
+        self.spec = spec
+
+    @property
+    def path(self):
+        return self.spec.origin
+
+    def get_resource_reader(self, name):
+        from . import readers, _adapters
+
+        def _zip_reader(spec):
+            with suppress(AttributeError):
+                return readers.ZipReader(spec.loader, spec.name)
+
+        def _namespace_reader(spec):
+            with suppress(AttributeError, ValueError):
+                return readers.NamespaceReader(spec.submodule_search_locations)
+
+        def _available_reader(spec):
+            with suppress(AttributeError):
+                return spec.loader.get_resource_reader(spec.name)
+
+        def _native_reader(spec):
+            reader = _available_reader(spec)
+            return reader if hasattr(reader, 'files') else None
+
+        def _file_reader(spec):
+            try:
+                path = pathlib.Path(self.path)
+            except TypeError:
+                return None
+            if path.exists():
+                return readers.FileReader(self)
+
+        return (
+            # native reader if it supplies 'files'
+            _native_reader(self.spec)
+            or
+            # local ZipReader if a zip module
+            _zip_reader(self.spec)
+            or
+            # local NamespaceReader if a namespace module
+            _namespace_reader(self.spec)
+            or
+            # local FileReader
+            _file_reader(self.spec)
+            # fallback - adapt the spec ResourceReader to TraversableReader
+            or _adapters.CompatibilityFiles(self.spec)
+        )
+
+
+def wrap_spec(package):
+    """
+    Construct a package spec with traversable compatibility
+    on the spec/loader/reader.
+
+    Supersedes _adapters.wrap_spec to use TraversableResourcesLoader
+    from above for older Python compatibility (<3.10).
+    """
+    from . import _adapters
+
+    return _adapters.SpecLoaderAdapter(package.__spec__, TraversableResourcesLoader)
+
+
+if sys.version_info >= (3, 9):
+    StrPath = Union[str, os.PathLike[str]]
+else:
+    # PathLike is only subscriptable at runtime in 3.9+
+    StrPath = Union[str, "os.PathLike[str]"]
diff --git a/third_party/python/setuptools/pkg_resources/_vendor/importlib_resources/_itertools.py b/third_party/python/setuptools/pkg_resources/_vendor/importlib_resources/_itertools.py
new file mode 100644
index 0000000000..cce05582ff
--- /dev/null
+++ b/third_party/python/setuptools/pkg_resources/_vendor/importlib_resources/_itertools.py
@@ -0,0 +1,35 @@
+from itertools import filterfalse
+
+from typing import (
+    Callable,
+    Iterable,
+    Iterator,
+    Optional,
+    Set,
+    TypeVar,
+    Union,
+)
+
+# Type and type variable definitions
+_T = TypeVar('_T')
+_U = TypeVar('_U')
+
+
+def unique_everseen(
+    iterable: Iterable[_T], key: Optional[Callable[[_T], _U]] = None
+) -> Iterator[_T]:
+    "List unique elements, preserving order. Remember all elements ever seen."
+    # unique_everseen('AAAABBBCCDAABBB') --> A B C D
+    # unique_everseen('ABBCcAD', str.lower) --> A B C D
+    seen: Set[Union[_T, _U]] = set()
+    seen_add = seen.add
+    if key is None:
+        for element in filterfalse(seen.__contains__, iterable):
+            seen_add(element)
+            yield element
+    else:
+        for element in iterable:
+            k = key(element)
+            if k not in seen:
+                seen_add(k)
+                yield element
diff --git a/third_party/python/setuptools/pkg_resources/_vendor/importlib_resources/_legacy.py b/third_party/python/setuptools/pkg_resources/_vendor/importlib_resources/_legacy.py
new file mode 100644
index 0000000000..b1ea8105da
--- /dev/null
+++ b/third_party/python/setuptools/pkg_resources/_vendor/importlib_resources/_legacy.py
@@ -0,0 +1,120 @@
+import functools
+import os
+import pathlib
+import types
+import warnings
+
+from typing import Union, Iterable, ContextManager, BinaryIO, TextIO, Any
+
+from . import _common
+
+Package = Union[types.ModuleType, str]
+Resource = str
+
+
+def deprecated(func):
+    @functools.wraps(func)
+    def wrapper(*args, **kwargs):
+        warnings.warn(
+            f"{func.__name__} is deprecated. Use files() instead. "
+            "Refer to https://importlib-resources.readthedocs.io"
+            "/en/latest/using.html#migrating-from-legacy for migration advice.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        return func(*args, **kwargs)
+
+    return wrapper
+
+
+def normalize_path(path: Any) -> str:
+    """Normalize a path by ensuring it is a string.
+
+    If the resulting string contains path separators, an exception is raised.
+    """
+    str_path = str(path)
+    parent, file_name = os.path.split(str_path)
+    if parent:
+        raise ValueError(f'{path!r} must be only a file name')
+    return file_name
+
+
+@deprecated
+def open_binary(package: Package, resource: Resource) -> BinaryIO:
+    """Return a file-like object opened for binary reading of the resource."""
+    return (_common.files(package) / normalize_path(resource)).open('rb')
+
+
+@deprecated
+def read_binary(package: Package, resource: Resource) -> bytes:
+    """Return the binary contents of the resource."""
+    return (_common.files(package) / normalize_path(resource)).read_bytes()
+
+
+@deprecated
+def open_text(
+    package: Package,
+    resource: Resource,
+    encoding: str = 'utf-8',
+    errors: str = 'strict',
+) -> TextIO:
+    """Return a file-like object opened for text reading of the resource."""
+    return (_common.files(package) / normalize_path(resource)).open(
+        'r', encoding=encoding, errors=errors
+    )
+
+
+@deprecated
+def read_text(
+    package: Package,
+    resource: Resource,
+    encoding: str = 'utf-8',
+    errors: str = 'strict',
+) -> str:
+    """Return the decoded string of the resource.
+
+    The decoding-related arguments have the same semantics as those of
+    bytes.decode().
+    """
+    with open_text(package, resource, encoding, errors) as fp:
+        return fp.read()
+
+
+@deprecated
+def contents(package: Package) -> Iterable[str]:
+    """Return an iterable of entries in `package`.
+
+    Note that not all entries are resources.  Specifically, directories are
+    not considered resources.  Use `is_resource()` on each entry returned here
+    to check if it is a resource or not.
+    """
+    return [path.name for path in _common.files(package).iterdir()]
+
+
+@deprecated
+def is_resource(package: Package, name: str) -> bool:
+    """True if `name` is a resource inside `package`.
+
+    Directories are *not* resources.
+    """
+    resource = normalize_path(name)
+    return any(
+        traversable.name == resource and traversable.is_file()
+        for traversable in _common.files(package).iterdir()
+    )
+
+
+@deprecated
+def path(
+    package: Package,
+    resource: Resource,
+) -> ContextManager[pathlib.Path]:
+    """A context manager providing a file path object to the resource.
+
+    If the resource does not already exist on its own on the file system,
+    a temporary file will be created. If the file was created, the file
+    will be deleted upon exiting the context manager (no exception is
+    raised if the file was deleted prior to the context manager
+    exiting).
+    """
+    return _common.as_file(_common.files(package) / normalize_path(resource))
diff --git a/third_party/python/setuptools/pkg_resources/_vendor/importlib_resources/abc.py b/third_party/python/setuptools/pkg_resources/_vendor/importlib_resources/abc.py
new file mode 100644
index 0000000000..23b6aeafe4
--- /dev/null
+++ b/third_party/python/setuptools/pkg_resources/_vendor/importlib_resources/abc.py
@@ -0,0 +1,170 @@
+import abc
+import io
+import itertools
+import pathlib
+from typing import Any, BinaryIO, Iterable, Iterator, NoReturn, Text, Optional
+
+from ._compat import runtime_checkable, Protocol, StrPath
+
+
+__all__ = ["ResourceReader", "Traversable", "TraversableResources"]
+
+
+class ResourceReader(metaclass=abc.ABCMeta):
+    """Abstract base class for loaders to provide resource reading support."""
+
+    @abc.abstractmethod
+    def open_resource(self, resource: Text) -> BinaryIO:
+        """Return an opened, file-like object for binary reading.
+
+        The 'resource' argument is expected to represent only a file name.
+        If the resource cannot be found, FileNotFoundError is raised.
+        """
+        # This deliberately raises FileNotFoundError instead of
+        # NotImplementedError so that if this method is accidentally called,
+        # it'll still do the right thing.
+        raise FileNotFoundError
+
+    @abc.abstractmethod
+    def resource_path(self, resource: Text) -> Text:
+        """Return the file system path to the specified resource.
+
+        The 'resource' argument is expected to represent only a file name.
+        If the resource does not exist on the file system, raise
+        FileNotFoundError.
+        """
+        # This deliberately raises FileNotFoundError instead of
+        # NotImplementedError so that if this method is accidentally called,
+        # it'll still do the right thing.
+        raise FileNotFoundError
+
+    @abc.abstractmethod
+    def is_resource(self, path: Text) -> bool:
+        """Return True if the named 'path' is a resource.
+
+        Files are resources, directories are not.
+        """
+        raise FileNotFoundError
+
+    @abc.abstractmethod
+    def contents(self) -> Iterable[str]:
+        """Return an iterable of entries in `package`."""
+        raise FileNotFoundError
+
+
+class TraversalError(Exception):
+    pass
+
+
+@runtime_checkable
+class Traversable(Protocol):
+    """
+    An object with a subset of pathlib.Path methods suitable for
+    traversing directories and opening files.
+
+    Any exceptions that occur when accessing the backing resource
+    may propagate unaltered.
+    """
+
+    @abc.abstractmethod
+    def iterdir(self) -> Iterator["Traversable"]:
+        """
+        Yield Traversable objects in self
+        """
+
+    def read_bytes(self) -> bytes:
+        """
+        Read contents of self as bytes
+        """
+        with self.open('rb') as strm:
+            return strm.read()
+
+    def read_text(self, encoding: Optional[str] = None) -> str:
+        """
+        Read contents of self as text
+        """
+        with self.open(encoding=encoding) as strm:
+            return strm.read()
+
+    @abc.abstractmethod
+    def is_dir(self) -> bool:
+        """
+        Return True if self is a directory
+        """
+
+    @abc.abstractmethod
+    def is_file(self) -> bool:
+        """
+        Return True if self is a file
+        """
+
+    def joinpath(self, *descendants: StrPath) -> "Traversable":
+        """
+        Return Traversable resolved with any descendants applied.
+
+        Each descendant should be a path segment relative to self
+        and each may contain multiple levels separated by
+        ``posixpath.sep`` (``/``).
+        """
+        if not descendants:
+            return self
+        names = itertools.chain.from_iterable(
+            path.parts for path in map(pathlib.PurePosixPath, descendants)
+        )
+        target = next(names)
+        matches = (
+            traversable for traversable in self.iterdir() if traversable.name == target
+        )
+        try:
+            match = next(matches)
+        except StopIteration:
+            raise TraversalError(
+                "Target not found during traversal.", target, list(names)
+            )
+        return match.joinpath(*names)
+
+    def __truediv__(self, child: StrPath) -> "Traversable":
+        """
+        Return Traversable child in self
+        """
+        return self.joinpath(child)
+
+    @abc.abstractmethod
+    def open(self, mode='r', *args, **kwargs):
+        """
+        mode may be 'r' or 'rb' to open as text or binary. Return a handle
+        suitable for reading (same as pathlib.Path.open).
+
+        When opening as text, accepts encoding parameters such as those
+        accepted by io.TextIOWrapper.
+        """
+
+    @property
+    @abc.abstractmethod
+    def name(self) -> str:
+        """
+        The base name of this object without any parent references.
+        """
+
+
+class TraversableResources(ResourceReader):
+    """
+    The required interface for providing traversable
+    resources.
+    """
+
+    @abc.abstractmethod
+    def files(self) -> "Traversable":
+        """Return a Traversable object for the loaded package."""
+
+    def open_resource(self, resource: StrPath) -> io.BufferedReader:
+        return self.files().joinpath(resource).open('rb')
+
+    def resource_path(self, resource: Any) -> NoReturn:
+        raise FileNotFoundError(resource)
+
+    def is_resource(self, path: StrPath) -> bool:
+        return self.files().joinpath(path).is_file()
+
+    def contents(self) -> Iterator[str]:
+        return (item.name for item in self.files().iterdir())
diff --git a/third_party/python/setuptools/pkg_resources/_vendor/importlib_resources/readers.py b/third_party/python/setuptools/pkg_resources/_vendor/importlib_resources/readers.py
new file mode 100644
index 0000000000..ab34db7409
--- /dev/null
+++ b/third_party/python/setuptools/pkg_resources/_vendor/importlib_resources/readers.py
@@ -0,0 +1,120 @@
+import collections
+import pathlib
+import operator
+
+from . import abc
+
+from ._itertools import unique_everseen
+from ._compat import ZipPath
+
+
+def remove_duplicates(items):
+    return iter(collections.OrderedDict.fromkeys(items))
+
+
+class FileReader(abc.TraversableResources):
+    def __init__(self, loader):
+        self.path = pathlib.Path(loader.path).parent
+
+    def resource_path(self, resource):
+        """
+        Return the file system path to prevent
+        `resources.path()` from creating a temporary
+        copy.
+        """
+        return str(self.path.joinpath(resource))
+
+    def files(self):
+        return self.path
+
+
+class ZipReader(abc.TraversableResources):
+    def __init__(self, loader, module):
+        _, _, name = module.rpartition('.')
+        self.prefix = loader.prefix.replace('\\', '/') + name + '/'
+        self.archive = loader.archive
+
+    def open_resource(self, resource):
+        try:
+            return super().open_resource(resource)
+        except KeyError as exc:
+            raise FileNotFoundError(exc.args[0])
+
+    def is_resource(self, path):
+        # workaround for `zipfile.Path.is_file` returning true
+        # for non-existent paths.
+        target = self.files().joinpath(path)
+        return target.is_file() and target.exists()
+
+    def files(self):
+        return ZipPath(self.archive, self.prefix)
+
+
+class MultiplexedPath(abc.Traversable):
+    """
+    Given a series of Traversable objects, implement a merged
+    version of the interface across all objects. Useful for
+    namespace packages which may be multihomed at a single
+    name.
+    """
+
+    def __init__(self, *paths):
+        self._paths = list(map(pathlib.Path, remove_duplicates(paths)))
+        if not self._paths:
+            message = 'MultiplexedPath must contain at least one path'
+            raise FileNotFoundError(message)
+        if not all(path.is_dir() for path in self._paths):
+            raise NotADirectoryError('MultiplexedPath only supports directories')
+
+    def iterdir(self):
+        files = (file for path in self._paths for file in path.iterdir())
+        return unique_everseen(files, key=operator.attrgetter('name'))
+
+    def read_bytes(self):
+        raise FileNotFoundError(f'{self} is not a file')
+
+    def read_text(self, *args, **kwargs):
+        raise FileNotFoundError(f'{self} is not a file')
+
+    def is_dir(self):
+        return True
+
+    def is_file(self):
+        return False
+
+    def joinpath(self, *descendants):
+        try:
+            return super().joinpath(*descendants)
+        except abc.TraversalError:
+            # One of the paths did not resolve (a directory does not exist).
+            # Just return something that will not exist.
+            return self._paths[0].joinpath(*descendants)
+
+    def open(self, *args, **kwargs):
+        raise FileNotFoundError(f'{self} is not a file')
+
+    @property
+    def name(self):
+        return self._paths[0].name
+
+    def __repr__(self):
+        paths = ', '.join(f"'{path}'" for path in self._paths)
+        return f'MultiplexedPath({paths})'
+
+
+class NamespaceReader(abc.TraversableResources):
+    def __init__(self, namespace_path):
+        if 'NamespacePath' not in str(namespace_path):
+            raise ValueError('Invalid path')
+        self.path = MultiplexedPath(*list(namespace_path))
+
+    def resource_path(self, resource):
+        """
+        Return the file system path to prevent
+        `resources.path()` from creating a temporary
+        copy.
+        """
+        return str(self.path.joinpath(resource))
+
+    def files(self):
+        return self.path
diff --git a/third_party/python/setuptools/pkg_resources/_vendor/importlib_resources/simple.py b/third_party/python/setuptools/pkg_resources/_vendor/importlib_resources/simple.py
new file mode 100644
index 0000000000..7770c922c8
--- /dev/null
+++ b/third_party/python/setuptools/pkg_resources/_vendor/importlib_resources/simple.py
@@ -0,0 +1,106 @@
+"""
+Interface adapters for low-level readers.
+"""
+
+import abc
+import io
+import itertools
+from typing import BinaryIO, List
+
+from .abc import Traversable, TraversableResources
+
+
+class SimpleReader(abc.ABC):
+    """
+    The minimum, low-level interface required from a resource
+    provider.
+    """
+
+    @property
+    @abc.abstractmethod
+    def package(self) -> str:
+        """
+        The name of the package for which this reader loads resources.
+        """
+
+    @abc.abstractmethod
+    def children(self) -> List['SimpleReader']:
+        """
+        Obtain an iterable of SimpleReader for available
+        child containers (e.g. directories).
+        """
+
+    @abc.abstractmethod
+    def resources(self) -> List[str]:
+        """
+        Obtain available named resources for this virtual package.
+        """
+
+    @abc.abstractmethod
+    def open_binary(self, resource: str) -> BinaryIO:
+        """
+        Obtain a File-like for a named resource.
+        """
+
+    @property
+    def name(self):
+        return self.package.split('.')[-1]
+
+
+class ResourceContainer(Traversable):
+    """
+    Traversable container for a package's resources via its reader.
+    """
+
+    def __init__(self, reader: SimpleReader):
+        self.reader = reader
+
+    def is_dir(self):
+        return True
+
+    def is_file(self):
+        return False
+
+    def iterdir(self):
+        files = (ResourceHandle(self, name) for name in self.reader.resources)
+        dirs = map(ResourceContainer, self.reader.children())
+        return itertools.chain(files, dirs)
+
+    def open(self, *args, **kwargs):
+        raise IsADirectoryError()
+
+
+class ResourceHandle(Traversable):
+    """
+    Handle to a named resource in a ResourceReader.
+    """
+
+    def __init__(self, parent: ResourceContainer, name: str):
+        self.parent = parent
+        self.name = name  # type: ignore
+
+    def is_file(self):
+        return True
+
+    def is_dir(self):
+        return False
+
+    def open(self, mode='r', *args, **kwargs):
+        stream = self.parent.reader.open_binary(self.name)
+        if 'b' not in mode:
+            stream = io.TextIOWrapper(*args, **kwargs)
+        return stream
+
+    def joinpath(self, name):
+        raise RuntimeError("Cannot traverse into a resource")
+
+
+class TraversableReader(TraversableResources, SimpleReader):
+    """
+    A TraversableResources based on SimpleReader. Resource providers
+    may derive from this class to provide the TraversableResources
+    interface by supplying the SimpleReader interface.
+    """
+
+    def files(self):
+        return ResourceContainer(self)
diff --git a/third_party/python/setuptools/pkg_resources/_vendor/jaraco/__init__.py b/third_party/python/setuptools/pkg_resources/_vendor/jaraco/__init__.py
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/third_party/python/setuptools/pkg_resources/_vendor/jaraco/__init__.py
diff --git a/third_party/python/setuptools/pkg_resources/_vendor/jaraco/context.py b/third_party/python/setuptools/pkg_resources/_vendor/jaraco/context.py
new file mode 100644
index 0000000000..b0d1ef37cb
--- /dev/null
+++ b/third_party/python/setuptools/pkg_resources/_vendor/jaraco/context.py
@@ -0,0 +1,288 @@
+import os
+import subprocess
+import contextlib
+import functools
+import tempfile
+import shutil
+import operator
+import warnings
+
+
+@contextlib.contextmanager
+def pushd(dir):
+    """
+    >>> tmp_path = getfixture('tmp_path')
+    >>> with pushd(tmp_path):
+    ...     assert os.getcwd() == os.fspath(tmp_path)
+    >>> assert os.getcwd() != os.fspath(tmp_path)
+    """
+
+    orig = os.getcwd()
+    os.chdir(dir)
+    try:
+        yield dir
+    finally:
+        os.chdir(orig)
+
+
+@contextlib.contextmanager
+def tarball_context(url, target_dir=None, runner=None, pushd=pushd):
+    """
+    Get a tarball, extract it, change to that directory, yield, then
+    clean up.
+    `runner` is the function to invoke commands.
+    `pushd` is a context manager for changing the directory.
+    """
+    if target_dir is None:
+        target_dir = os.path.basename(url).replace('.tar.gz', '').replace('.tgz', '')
+    if runner is None:
+        runner = functools.partial(subprocess.check_call, shell=True)
+    else:
+        warnings.warn("runner parameter is deprecated", DeprecationWarning)
+    # In the tar command, use --strip-components=1 to strip the first path and
+    #  then
+    #  use -C to cause the files to be extracted to {target_dir}. This ensures
+    #  that we always know where the files were extracted.
+    runner('mkdir {target_dir}'.format(**vars()))
+    try:
+        getter = 'wget {url} -O -'
+        extract = 'tar x{compression} --strip-components=1 -C {target_dir}'
+        cmd = ' | '.join((getter, extract))
+        runner(cmd.format(compression=infer_compression(url), **vars()))
+        with pushd(target_dir):
+            yield target_dir
+    finally:
+        runner('rm -Rf {target_dir}'.format(**vars()))
+
+
+def infer_compression(url):
+    """
+    Given a URL or filename, infer the compression code for tar.
+
+    >>> infer_compression('http://foo/bar.tar.gz')
+    'z'
+    >>> infer_compression('http://foo/bar.tgz')
+    'z'
+    >>> infer_compression('file.bz')
+    'j'
+    >>> infer_compression('file.xz')
+    'J'
+    """
+    # cheat and just assume it's the last two characters
+    compression_indicator = url[-2:]
+    mapping = dict(gz='z', bz='j', xz='J')
+    # Assume 'z' (gzip) if no match
+    return mapping.get(compression_indicator, 'z')
+
+
+@contextlib.contextmanager
+def temp_dir(remover=shutil.rmtree):
+    """
+    Create a temporary directory context. Pass a custom remover
+    to override the removal behavior.
+
+    >>> import pathlib
+    >>> with temp_dir() as the_dir:
+    ...     assert os.path.isdir(the_dir)
+    ...     _ = pathlib.Path(the_dir).joinpath('somefile').write_text('contents')
+    >>> assert not os.path.exists(the_dir)
+    """
+    temp_dir = tempfile.mkdtemp()
+    try:
+        yield temp_dir
+    finally:
+        remover(temp_dir)
+
+
+@contextlib.contextmanager
+def repo_context(url, branch=None, quiet=True, dest_ctx=temp_dir):
+    """
+    Check out the repo indicated by url.
+
+    If dest_ctx is supplied, it should be a context manager
+    to yield the target directory for the check out.
+    """
+    exe = 'git' if 'git' in url else 'hg'
+    with dest_ctx() as repo_dir:
+        cmd = [exe, 'clone', url, repo_dir]
+        if branch:
+            cmd.extend(['--branch', branch])
+        devnull = open(os.path.devnull, 'w')
+        stdout = devnull if quiet else None
+        subprocess.check_call(cmd, stdout=stdout)
+        yield repo_dir
+
+
+@contextlib.contextmanager
+def null():
+    """
+    A null context suitable to stand in for a meaningful context.
+
+    >>> with null() as value:
+    ...     assert value is None
+    """
+    yield
+
+
+class ExceptionTrap:
+    """
+    A context manager that will catch certain exceptions and provide an
+    indication they occurred.
+
+    >>> with ExceptionTrap() as trap:
+    ...     raise Exception()
+    >>> bool(trap)
+    True
+
+    >>> with ExceptionTrap() as trap:
+    ...     pass
+    >>> bool(trap)
+    False
+
+    >>> with ExceptionTrap(ValueError) as trap:
+    ...     raise ValueError("1 + 1 is not 3")
+    >>> bool(trap)
+    True
+    >>> trap.value
+    ValueError('1 + 1 is not 3')
+    >>> trap.tb
+    <traceback object at ...>
+
+    >>> with ExceptionTrap(ValueError) as trap:
+    ...     raise Exception()
+    Traceback (most recent call last):
+    ...
+    Exception
+
+    >>> bool(trap)
+    False
+    """
+
+    exc_info = None, None, None
+
+    def __init__(self, exceptions=(Exception,)):
+        self.exceptions = exceptions
+
+    def __enter__(self):
+        return self
+
+    @property
+    def type(self):
+        return self.exc_info[0]
+
+    @property
+    def value(self):
+        return self.exc_info[1]
+
+    @property
+    def tb(self):
+        return self.exc_info[2]
+
+    def __exit__(self, *exc_info):
+        type = exc_info[0]
+        matches = type and issubclass(type, self.exceptions)
+        if matches:
+            self.exc_info = exc_info
+        return matches
+
+    def __bool__(self):
+        return bool(self.type)
+
+    def raises(self, func, *, _test=bool):
+        """
+        Wrap func and replace the result with the truth
+        value of the trap (True if an exception occurred).
+
+        First, give the decorator an alias to support Python 3.8
+        Syntax.
+
+        >>> raises = ExceptionTrap(ValueError).raises
+
+        Now decorate a function that always fails.
+
+        >>> @raises
+        ... def fail():
+        ...     raise ValueError('failed')
+        >>> fail()
+        True
+        """
+
+        @functools.wraps(func)
+        def wrapper(*args, **kwargs):
+            with ExceptionTrap(self.exceptions) as trap:
+                func(*args, **kwargs)
+            return _test(trap)
+
+        return wrapper
+
+    def passes(self, func):
+        """
+        Wrap func and replace the result with the truth
+        value of the trap (True if no exception).
+
+        First, give the decorator an alias to support Python 3.8
+        Syntax.
+
+        >>> passes = ExceptionTrap(ValueError).passes
+
+        Now decorate a function that always fails.
+
+        >>> @passes
+        ... def fail():
+        ...     raise ValueError('failed')
+
+        >>> fail()
+        False
+        """
+        return self.raises(func, _test=operator.not_)
+
+
+class suppress(contextlib.suppress, contextlib.ContextDecorator):
+    """
+    A version of contextlib.suppress with decorator support.
+
+    >>> @suppress(KeyError)
+    ... def key_error():
+    ...     {}['']
+    >>> key_error()
+    """
+
+
+class on_interrupt(contextlib.ContextDecorator):
+    """
+    Replace a KeyboardInterrupt with SystemExit(1)
+
+    >>> def do_interrupt():
+    ...     raise KeyboardInterrupt()
+    >>> on_interrupt('error')(do_interrupt)()
+    Traceback (most recent call last):
+    ...
+    SystemExit: 1
+    >>> on_interrupt('error', code=255)(do_interrupt)()
+    Traceback (most recent call last):
+    ...
+    SystemExit: 255
+    >>> on_interrupt('suppress')(do_interrupt)()
+    >>> with __import__('pytest').raises(KeyboardInterrupt):
+    ...     on_interrupt('ignore')(do_interrupt)()
+    """
+
+    def __init__(
+        self,
+        action='error',
+        # py3.7 compat
+        # /,
+        code=1,
+    ):
+        self.action = action
+        self.code = code
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, exctype, excinst, exctb):
+        if exctype is not KeyboardInterrupt or self.action == 'ignore':
+            return
+        elif self.action == 'error':
+            raise SystemExit(self.code) from excinst
+        return self.action == 'suppress'
diff --git a/third_party/python/setuptools/pkg_resources/_vendor/jaraco/functools.py b/third_party/python/setuptools/pkg_resources/_vendor/jaraco/functools.py
new file mode 100644
index 0000000000..67aeadc353
--- /dev/null
+++ b/third_party/python/setuptools/pkg_resources/_vendor/jaraco/functools.py
@@ -0,0 +1,556 @@
+import functools
+import time
+import inspect
+import collections
+import types
+import itertools
+import warnings
+
+import pkg_resources.extern.more_itertools
+
+from typing import Callable, TypeVar
+
+
+CallableT = TypeVar("CallableT", bound=Callable[..., object])
+
+
+def compose(*funcs):
+    """
+    Compose any number of unary functions into a single unary function.
+
+    >>> import textwrap
+    >>> expected = str.strip(textwrap.dedent(compose.__doc__))
+    >>> strip_and_dedent = compose(str.strip, textwrap.dedent)
+    >>> strip_and_dedent(compose.__doc__) == expected
+    True
+
+    Compose also allows the innermost function to take arbitrary arguments.
+
+    >>> round_three = lambda x: round(x, ndigits=3)
+    >>> f = compose(round_three, int.__truediv__)
+    >>> [f(3*x, x+1) for x in range(1,10)]
+    [1.5, 2.0, 2.25, 2.4, 2.5, 2.571, 2.625, 2.667, 2.7]
+    """
+
+    def compose_two(f1, f2):
+        return lambda *args, **kwargs: f1(f2(*args, **kwargs))
+
+    return functools.reduce(compose_two, funcs)
+
+
+def method_caller(method_name, *args, **kwargs):
+    """
+    Return a function that will call a named method on the
+    target object with optional positional and keyword
+    arguments.
+
+    >>> lower = method_caller('lower')
+    >>> lower('MyString')
+    'mystring'
+    """
+
+    def call_method(target):
+        func = getattr(target, method_name)
+        return func(*args, **kwargs)
+
+    return call_method
+
+
+def once(func):
+    """
+    Decorate func so it's only ever called the first time.
+
+    This decorator can ensure that an expensive or non-idempotent function
+    will not be expensive on subsequent calls and is idempotent.
+
+    >>> add_three = once(lambda a: a+3)
+    >>> add_three(3)
+    6
+    >>> add_three(9)
+    6
+    >>> add_three('12')
+    6
+
+    To reset the stored value, simply clear the property ``saved_result``.
+
+    >>> del add_three.saved_result
+    >>> add_three(9)
+    12
+    >>> add_three(8)
+    12
+
+    Or invoke 'reset()' on it.
+
+    >>> add_three.reset()
+    >>> add_three(-3)
+    0
+    >>> add_three(0)
+    0
+    """
+
+    @functools.wraps(func)
+    def wrapper(*args, **kwargs):
+        if not hasattr(wrapper, 'saved_result'):
+            wrapper.saved_result = func(*args, **kwargs)
+        return wrapper.saved_result
+
+    wrapper.reset = lambda: vars(wrapper).__delitem__('saved_result')
+    return wrapper
+
+
+def method_cache(
+    method: CallableT,
+    cache_wrapper: Callable[
+        [CallableT], CallableT
+    ] = functools.lru_cache(),  # type: ignore[assignment]
+) -> CallableT:
+    """
+    Wrap lru_cache to support storing the cache data in the object instances.
+
+    Abstracts the common paradigm where the method explicitly saves an
+    underscore-prefixed protected property on first call and returns that
+    subsequently.
+
+    >>> class MyClass:
+    ...     calls = 0
+    ...
+    ...     @method_cache
+    ...     def method(self, value):
+    ...         self.calls += 1
+    ...         return value
+
+    >>> a = MyClass()
+    >>> a.method(3)
+    3
+    >>> for x in range(75):
+    ...     res = a.method(x)
+    >>> a.calls
+    75
+
+    Note that the apparent behavior will be exactly like that of lru_cache
+    except that the cache is stored on each instance, so values in one
+    instance will not flush values from another, and when an instance is
+    deleted, so are the cached values for that instance.
+
+    >>> b = MyClass()
+    >>> for x in range(35):
+    ...     res = b.method(x)
+    >>> b.calls
+    35
+    >>> a.method(0)
+    0
+    >>> a.calls
+    75
+
+    Note that if method had been decorated with ``functools.lru_cache()``,
+    a.calls would have been 76 (due to the cached value of 0 having been
+    flushed by the 'b' instance).
+
+    Clear the cache with ``.cache_clear()``
+
+    >>> a.method.cache_clear()
+
+    Same for a method that hasn't yet been called.
+
+    >>> c = MyClass()
+    >>> c.method.cache_clear()
+
+    Another cache wrapper may be supplied:
+
+    >>> cache = functools.lru_cache(maxsize=2)
+    >>> MyClass.method2 = method_cache(lambda self: 3, cache_wrapper=cache)
+    >>> a = MyClass()
+    >>> a.method2()
+    3
+
+    Caution - do not subsequently wrap the method with another decorator, such
+    as ``@property``, which changes the semantics of the function.
+
+    See also
+    http://code.activestate.com/recipes/577452-a-memoize-decorator-for-instance-methods/
+    for another implementation and additional justification.
+    """
+
+    def wrapper(self: object, *args: object, **kwargs: object) -> object:
+        # it's the first call, replace the method with a cached, bound method
+        bound_method: CallableT = types.MethodType(  # type: ignore[assignment]
+            method, self
+        )
+        cached_method = cache_wrapper(bound_method)
+        setattr(self, method.__name__, cached_method)
+        return cached_method(*args, **kwargs)
+
+    # Support cache clear even before cache has been created.
+    wrapper.cache_clear = lambda: None  # type: ignore[attr-defined]
+
+    return (  # type: ignore[return-value]
+        _special_method_cache(method, cache_wrapper) or wrapper
+    )
+
+
+def _special_method_cache(method, cache_wrapper):
+    """
+    Because Python treats special methods differently, it's not
+    possible to use instance attributes to implement the cached
+    methods.
+
+    Instead, install the wrapper method under a different name
+    and return a simple proxy to that wrapper.
+
+    https://github.com/jaraco/jaraco.functools/issues/5
+    """
+    name = method.__name__
+    special_names = '__getattr__', '__getitem__'
+    if name not in special_names:
+        return
+
+    wrapper_name = '__cached' + name
+
+    def proxy(self, *args, **kwargs):
+        if wrapper_name not in vars(self):
+            bound = types.MethodType(method, self)
+            cache = cache_wrapper(bound)
+            setattr(self, wrapper_name, cache)
+        else:
+            cache = getattr(self, wrapper_name)
+        return cache(*args, **kwargs)
+
+    return proxy
+
+
+def apply(transform):
+    """
+    Decorate a function with a transform function that is
+    invoked on results returned from the decorated function.
+
+    >>> @apply(reversed)
+    ... def get_numbers(start):
+    ...     "doc for get_numbers"
+    ...     return range(start, start+3)
+    >>> list(get_numbers(4))
+    [6, 5, 4]
+    >>> get_numbers.__doc__
+    'doc for get_numbers'
+    """
+
+    def wrap(func):
+        return functools.wraps(func)(compose(transform, func))
+
+    return wrap
+
+
+def result_invoke(action):
+    r"""
+    Decorate a function with an action function that is
+    invoked on the results returned from the decorated
+    function (for its side-effect), then return the original
+    result.
+
+    >>> @result_invoke(print)
+    ... def add_two(a, b):
+    ...     return a + b
+    >>> x = add_two(2, 3)
+    5
+    >>> x
+    5
+    """
+
+    def wrap(func):
+        @functools.wraps(func)
+        def wrapper(*args, **kwargs):
+            result = func(*args, **kwargs)
+            action(result)
+            return result
+
+        return wrapper
+
+    return wrap
+
+
+def invoke(f, *args, **kwargs):
+    """
+    Call a function for its side effect after initialization.
+
+    The benefit of using the decorator instead of simply invoking a function
+    after defining it is that it makes explicit the author's intent for the
+    function to be called immediately. Whereas if one simply calls the
+    function immediately, it's less obvious if that was intentional or
+    incidental. It also avoids repeating the name - the two actions, defining
+    the function and calling it immediately are modeled separately, but linked
+    by the decorator construct.
+
+    The benefit of having a function construct (opposed to just invoking some
+    behavior inline) is to serve as a scope in which the behavior occurs. It
+    avoids polluting the global namespace with local variables, provides an
+    anchor on which to attach documentation (docstring), keeps the behavior
+    logically separated (instead of conceptually separated or not separated at
+    all), and provides potential to re-use the behavior for testing or other
+    purposes.
+
+    This function is named as a pithy way to communicate, "call this function
+    primarily for its side effect", or "while defining this function, also
+    take it aside and call it". It exists because there's no Python construct
+    for "define and call" (nor should there be, as decorators serve this need
+    just fine). The behavior happens immediately and synchronously.
+
+    >>> @invoke
+    ... def func(): print("called")
+    called
+    >>> func()
+    called
+
+    Use functools.partial to pass parameters to the initial call
+
+    >>> @functools.partial(invoke, name='bingo')
+    ... def func(name): print("called with", name)
+    called with bingo
+    """
+    f(*args, **kwargs)
+    return f
+
+
+def call_aside(*args, **kwargs):
+    """
+    Deprecated name for invoke.
+    """
+    warnings.warn("call_aside is deprecated, use invoke", DeprecationWarning)
+    return invoke(*args, **kwargs)
+
+
+class Throttler:
+    """
+    Rate-limit a function (or other callable)
+    """
+
+    def __init__(self, func, max_rate=float('Inf')):
+        if isinstance(func, Throttler):
+            func = func.func
+        self.func = func
+        self.max_rate = max_rate
+        self.reset()
+
+    def reset(self):
+        self.last_called = 0
+
+    def __call__(self, *args, **kwargs):
+        self._wait()
+        return self.func(*args, **kwargs)
+
+    def _wait(self):
+        "ensure at least 1/max_rate seconds from last call"
+        elapsed = time.time() - self.last_called
+        must_wait = 1 / self.max_rate - elapsed
+        time.sleep(max(0, must_wait))
+        self.last_called = time.time()
+
+    def __get__(self, obj, type=None):
+        return first_invoke(self._wait, functools.partial(self.func, obj))
+
+
+def first_invoke(func1, func2):
+    """
+    Return a function that when invoked will invoke func1 without
+    any parameters (for its side-effect) and then invoke func2
+    with whatever parameters were passed, returning its result.
+    """
+
+    def wrapper(*args, **kwargs):
+        func1()
+        return func2(*args, **kwargs)
+
+    return wrapper
+
+
+def retry_call(func, cleanup=lambda: None, retries=0, trap=()):
+    """
+    Given a callable func, trap the indicated exceptions
+    for up to 'retries' times, invoking cleanup on the
+    exception. On the final attempt, allow any exceptions
+    to propagate.
+    """
+    attempts = itertools.count() if retries == float('inf') else range(retries)
+    for attempt in attempts:
+        try:
+            return func()
+        except trap:
+            cleanup()
+
+    return func()
+
+
+def retry(*r_args, **r_kwargs):
+    """
+    Decorator wrapper for retry_call. Accepts arguments to retry_call
+    except func and then returns a decorator for the decorated function.
+
+    Ex:
+
+    >>> @retry(retries=3)
+    ... def my_func(a, b):
+    ...     "this is my funk"
+    ...     print(a, b)
+    >>> my_func.__doc__
+    'this is my funk'
+    """
+
+    def decorate(func):
+        @functools.wraps(func)
+        def wrapper(*f_args, **f_kwargs):
+            bound = functools.partial(func, *f_args, **f_kwargs)
+            return retry_call(bound, *r_args, **r_kwargs)
+
+        return wrapper
+
+    return decorate
+
+
+def print_yielded(func):
+    """
+    Convert a generator into a function that prints all yielded elements
+
+    >>> @print_yielded
+    ... def x():
+    ...     yield 3; yield None
+    >>> x()
+    3
+    None
+    """
+    print_all = functools.partial(map, print)
+    print_results = compose(more_itertools.consume, print_all, func)
+    return functools.wraps(func)(print_results)
+
+
+def pass_none(func):
+    """
+    Wrap func so it's not called if its first param is None
+
+    >>> print_text = pass_none(print)
+    >>> print_text('text')
+    text
+    >>> print_text(None)
+    """
+
+    @functools.wraps(func)
+    def wrapper(param, *args, **kwargs):
+        if param is not None:
+            return func(param, *args, **kwargs)
+
+    return wrapper
+
+
+def assign_params(func, namespace):
+    """
+    Assign parameters from namespace where func solicits.
+
+    >>> def func(x, y=3):
+    ...     print(x, y)
+    >>> assigned = assign_params(func, dict(x=2, z=4))
+    >>> assigned()
+    2 3
+
+    The usual errors are raised if a function doesn't receive
+    its required parameters:
+
+    >>> assigned = assign_params(func, dict(y=3, z=4))
+    >>> assigned()
+    Traceback (most recent call last):
+    TypeError: func() ...argument...
+
+    It even works on methods:
+
+    >>> class Handler:
+    ...     def meth(self, arg):
+    ...         print(arg)
+    >>> assign_params(Handler().meth, dict(arg='crystal', foo='clear'))()
+    crystal
+    """
+    sig = inspect.signature(func)
+    params = sig.parameters.keys()
+    call_ns = {k: namespace[k] for k in params if k in namespace}
+    return functools.partial(func, **call_ns)
+
+
+def save_method_args(method):
+    """
+    Wrap a method such that when it is called, the args and kwargs are
+    saved on the method.
+
+    >>> class MyClass:
+    ...     @save_method_args
+    ...     def method(self, a, b):
+    ...         print(a, b)
+    >>> my_ob = MyClass()
+    >>> my_ob.method(1, 2)
+    1 2
+    >>> my_ob._saved_method.args
+    (1, 2)
+    >>> my_ob._saved_method.kwargs
+    {}
+    >>> my_ob.method(a=3, b='foo')
+    3 foo
+    >>> my_ob._saved_method.args
+    ()
+    >>> my_ob._saved_method.kwargs == dict(a=3, b='foo')
+    True
+
+    The arguments are stored on the instance, allowing for
+    different instance to save different args.
+
+    >>> your_ob = MyClass()
+    >>> your_ob.method({str('x'): 3}, b=[4])
+    {'x': 3} [4]
+    >>> your_ob._saved_method.args
+    ({'x': 3},)
+    >>> my_ob._saved_method.args
+    ()
+    """
+    args_and_kwargs = collections.namedtuple('args_and_kwargs', 'args kwargs')
+
+    @functools.wraps(method)
+    def wrapper(self, *args, **kwargs):
+        attr_name = '_saved_' + method.__name__
+        attr = args_and_kwargs(args, kwargs)
+        setattr(self, attr_name, attr)
+        return method(self, *args, **kwargs)
+
+    return wrapper
+
+
+def except_(*exceptions, replace=None, use=None):
+    """
+    Replace the indicated exceptions, if raised, with the indicated
+    literal replacement or evaluated expression (if present).
+
+    >>> safe_int = except_(ValueError)(int)
+    >>> safe_int('five')
+    >>> safe_int('5')
+    5
+
+    Specify a literal replacement with ``replace``.
+
+    >>> safe_int_r = except_(ValueError, replace=0)(int)
+    >>> safe_int_r('five')
+    0
+
+    Provide an expression to ``use`` to pass through particular parameters.
+
+    >>> safe_int_pt = except_(ValueError, use='args[0]')(int)
+    >>> safe_int_pt('five')
+    'five'
+
+    """
+
+    def decorate(func):
+        @functools.wraps(func)
+        def wrapper(*args, **kwargs):
+            try:
+                return func(*args, **kwargs)
+            except exceptions:
+                try:
+                    return eval(use)
+                except TypeError:
+                    return replace
+
+        return wrapper
+
+    return decorate
diff --git a/third_party/python/setuptools/pkg_resources/_vendor/jaraco/text/__init__.py b/third_party/python/setuptools/pkg_resources/_vendor/jaraco/text/__init__.py
new file mode 100644
index 0000000000..c466378ceb
--- /dev/null
+++ b/third_party/python/setuptools/pkg_resources/_vendor/jaraco/text/__init__.py
@@ -0,0 +1,599 @@
+import re
+import itertools
+import textwrap
+import functools
+
+try:
+    from importlib.resources import files  # type: ignore
+except ImportError:  # pragma: nocover
+    from pkg_resources.extern.importlib_resources import files  # type: ignore
+
+from pkg_resources.extern.jaraco.functools import compose, method_cache
+from pkg_resources.extern.jaraco.context import ExceptionTrap
+
+
+def substitution(old, new):
+    """
+    Return a function that will perform a substitution on a string
+    """
+    return lambda s: s.replace(old, new)
+
+
+def multi_substitution(*substitutions):
+    """
+    Take a sequence of pairs specifying substitutions, and create
+    a function that performs those substitutions.
+
+    >>> multi_substitution(('foo', 'bar'), ('bar', 'baz'))('foo')
+    'baz'
+    """
+    substitutions = itertools.starmap(substitution, substitutions)
+    # compose function applies last function first, so reverse the
+    #  substitutions to get the expected order.
+    substitutions = reversed(tuple(substitutions))
+    return compose(*substitutions)
+
+
+class FoldedCase(str):
+    """
+    A case insensitive string class; behaves just like str
+    except compares equal when the only variation is case.
+
+    >>> s = FoldedCase('hello world')
+
+    >>> s == 'Hello World'
+    True
+
+    >>> 'Hello World' == s
+    True
+
+    >>> s != 'Hello World'
+    False
+
+    >>> s.index('O')
+    4
+
+    >>> s.split('O')
+    ['hell', ' w', 'rld']
+
+    >>> sorted(map(FoldedCase, ['GAMMA', 'alpha', 'Beta']))
+    ['alpha', 'Beta', 'GAMMA']
+
+    Sequence membership is straightforward.
+
+    >>> "Hello World" in [s]
+    True
+    >>> s in ["Hello World"]
+    True
+
+    You may test for set inclusion, but candidate and elements
+    must both be folded.
+
+    >>> FoldedCase("Hello World") in {s}
+    True
+    >>> s in {FoldedCase("Hello World")}
+    True
+
+    String inclusion works as long as the FoldedCase object
+    is on the right.
+
+    >>> "hello" in FoldedCase("Hello World")
+    True
+
+    But not if the FoldedCase object is on the left:
+
+    >>> FoldedCase('hello') in 'Hello World'
+    False
+
+    In that case, use ``in_``:
+
+    >>> FoldedCase('hello').in_('Hello World')
+    True
+
+    >>> FoldedCase('hello') > FoldedCase('Hello')
+    False
+    """
+
+    def __lt__(self, other):
+        return self.lower() < other.lower()
+
+    def __gt__(self, other):
+        return self.lower() > other.lower()
+
+    def __eq__(self, other):
+        return self.lower() == other.lower()
+
+    def __ne__(self, other):
+        return self.lower() != other.lower()
+
+    def __hash__(self):
+        return hash(self.lower())
+
+    def __contains__(self, other):
+        return super().lower().__contains__(other.lower())
+
+    def in_(self, other):
+        "Does self appear in other?"
+        return self in FoldedCase(other)
+
+    # cache lower since it's likely to be called frequently.
+    @method_cache
+    def lower(self):
+        return super().lower()
+
+    def index(self, sub):
+        return self.lower().index(sub.lower())
+
+    def split(self, splitter=' ', maxsplit=0):
+        pattern = re.compile(re.escape(splitter), re.I)
+        return pattern.split(self, maxsplit)
+
+
+# Python 3.8 compatibility
+_unicode_trap = ExceptionTrap(UnicodeDecodeError)
+
+
+@_unicode_trap.passes
+def is_decodable(value):
+    r"""
+    Return True if the supplied value is decodable (using the default
+    encoding).
+
+    >>> is_decodable(b'\xff')
+    False
+    >>> is_decodable(b'\x32')
+    True
+    """
+    value.decode()
+
+
+def is_binary(value):
+    r"""
+    Return True if the value appears to be binary (that is, it's a byte
+    string and isn't decodable).
+
+    >>> is_binary(b'\xff')
+    True
+    >>> is_binary('\xff')
+    False
+    """
+    return isinstance(value, bytes) and not is_decodable(value)
+
+
+def trim(s):
+    r"""
+    Trim something like a docstring to remove the whitespace that
+    is common due to indentation and formatting.
+
+    >>> trim("\n\tfoo = bar\n\t\tbar = baz\n")
+    'foo = bar\n\tbar = baz'
+    """
+    return textwrap.dedent(s).strip()
+
+
+def wrap(s):
+    """
+    Wrap lines of text, retaining existing newlines as
+    paragraph markers.
+
+    >>> print(wrap(lorem_ipsum))
+    Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do
+    eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad
+    minim veniam, quis nostrud exercitation ullamco laboris nisi ut
+    aliquip ex ea commodo consequat. Duis aute irure dolor in
+    reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla
+    pariatur. Excepteur sint occaecat cupidatat non proident, sunt in
+    culpa qui officia deserunt mollit anim id est laborum.
+    <BLANKLINE>
+    Curabitur pretium tincidunt lacus. Nulla gravida orci a odio. Nullam
+    varius, turpis et commodo pharetra, est eros bibendum elit, nec luctus
+    magna felis sollicitudin mauris. Integer in mauris eu nibh euismod
+    gravida. Duis ac tellus et risus vulputate vehicula. Donec lobortis
+    risus a elit. Etiam tempor. Ut ullamcorper, ligula eu tempor congue,
+    eros est euismod turpis, id tincidunt sapien risus a quam. Maecenas
+    fermentum consequat mi. Donec fermentum. Pellentesque malesuada nulla
+    a mi. Duis sapien sem, aliquet nec, commodo eget, consequat quis,
+    neque. Aliquam faucibus, elit ut dictum aliquet, felis nisl adipiscing
+    sapien, sed malesuada diam lacus eget erat. Cras mollis scelerisque
+    nunc. Nullam arcu. Aliquam consequat. Curabitur augue lorem, dapibus
+    quis, laoreet et, pretium ac, nisi. Aenean magna nisl, mollis quis,
+    molestie eu, feugiat in, orci. In hac habitasse platea dictumst.
+    """
+    paragraphs = s.splitlines()
+    wrapped = ('\n'.join(textwrap.wrap(para)) for para in paragraphs)
+    return '\n\n'.join(wrapped)
+
+
+def unwrap(s):
+    r"""
+    Given a multi-line string, return an unwrapped version.
+
+    >>> wrapped = wrap(lorem_ipsum)
+    >>> wrapped.count('\n')
+    20
+    >>> unwrapped = unwrap(wrapped)
+    >>> unwrapped.count('\n')
+    1
+    >>> print(unwrapped)
+    Lorem ipsum dolor sit amet, consectetur adipiscing ...
+    Curabitur pretium tincidunt lacus. Nulla gravida orci ...
+
+    """
+    paragraphs = re.split(r'\n\n+', s)
+    cleaned = (para.replace('\n', ' ') for para in paragraphs)
+    return '\n'.join(cleaned)
+
+
+
+
+class Splitter(object):
+    """object that will split a string with the given arguments for each call
+
+    >>> s = Splitter(',')
+    >>> s('hello, world, this is your, master calling')
+    ['hello', ' world', ' this is your', ' master calling']
+    """
+
+    def __init__(self, *args):
+        self.args = args
+
+    def __call__(self, s):
+        return s.split(*self.args)
+
+
+def indent(string, prefix=' ' * 4):
+    """
+    >>> indent('foo')
+    '    foo'
+    """
+    return prefix + string
+
+
+class WordSet(tuple):
+    """
+    Given an identifier, return the words that identifier represents,
+    whether in camel case, underscore-separated, etc.
+
+    >>> WordSet.parse("camelCase")
+    ('camel', 'Case')
+
+    >>> WordSet.parse("under_sep")
+    ('under', 'sep')
+
+    Acronyms should be retained
+
+    >>> WordSet.parse("firstSNL")
+    ('first', 'SNL')
+
+    >>> WordSet.parse("you_and_I")
+    ('you', 'and', 'I')
+
+    >>> WordSet.parse("A simple test")
+    ('A', 'simple', 'test')
+
+    Multiple caps should not interfere with the first cap of another word.
+
+    >>> WordSet.parse("myABCClass")
+    ('my', 'ABC', 'Class')
+
+    The result is a WordSet, so you can get the form you need.
+
+    >>> WordSet.parse("myABCClass").underscore_separated()
+    'my_ABC_Class'
+
+    >>> WordSet.parse('a-command').camel_case()
+    'ACommand'
+
+    >>> WordSet.parse('someIdentifier').lowered().space_separated()
+    'some identifier'
+
+    Slices of the result should return another WordSet.
+
+    >>> WordSet.parse('taken-out-of-context')[1:].underscore_separated()
+    'out_of_context'
+
+    >>> WordSet.from_class_name(WordSet()).lowered().space_separated()
+    'word set'
+
+    >>> example = WordSet.parse('figured it out')
+    >>> example.headless_camel_case()
+    'figuredItOut'
+    >>> example.dash_separated()
+    'figured-it-out'
+
+    """
+
+    _pattern = re.compile('([A-Z]?[a-z]+)|([A-Z]+(?![a-z]))')
+
+    def capitalized(self):
+        return WordSet(word.capitalize() for word in self)
+
+    def lowered(self):
+        return WordSet(word.lower() for word in self)
+
+    def camel_case(self):
+        return ''.join(self.capitalized())
+
+    def headless_camel_case(self):
+        words = iter(self)
+        first = next(words).lower()
+        new_words = itertools.chain((first,), WordSet(words).camel_case())
+        return ''.join(new_words)
+
+    def underscore_separated(self):
+        return '_'.join(self)
+
+    def dash_separated(self):
+        return '-'.join(self)
+
+    def space_separated(self):
+        return ' '.join(self)
+
+    def trim_right(self, item):
+        """
+        Remove the item from the end of the set.
+
+        >>> WordSet.parse('foo bar').trim_right('foo')
+        ('foo', 'bar')
+        >>> WordSet.parse('foo bar').trim_right('bar')
+        ('foo',)
+        >>> WordSet.parse('').trim_right('bar')
+        ()
+        """
+        return self[:-1] if self and self[-1] == item else self
+
+    def trim_left(self, item):
+        """
+        Remove the item from the beginning of the set.
+
+        >>> WordSet.parse('foo bar').trim_left('foo')
+        ('bar',)
+        >>> WordSet.parse('foo bar').trim_left('bar')
+        ('foo', 'bar')
+        >>> WordSet.parse('').trim_left('bar')
+        ()
+        """
+        return self[1:] if self and self[0] == item else self
+
+    def trim(self, item):
+        """
+        >>> WordSet.parse('foo bar').trim('foo')
+        ('bar',)
+        """
+        return self.trim_left(item).trim_right(item)
+
+    def __getitem__(self, item):
+        result = super(WordSet, self).__getitem__(item)
+        if isinstance(item, slice):
+            result = WordSet(result)
+        return result
+
+    @classmethod
+    def parse(cls, identifier):
+        matches = cls._pattern.finditer(identifier)
+        return WordSet(match.group(0) for match in matches)
+
+    @classmethod
+    def from_class_name(cls, subject):
+        return cls.parse(subject.__class__.__name__)
+
+
+# for backward compatibility
+words = WordSet.parse
+
+
+def simple_html_strip(s):
+    r"""
+    Remove HTML from the string `s`.
+
+    >>> str(simple_html_strip(''))
+    ''
+
+    >>> print(simple_html_strip('A <bold>stormy</bold> day in paradise'))
+    A stormy day in paradise
+
+    >>> print(simple_html_strip('Somebody <!-- do not --> tell the truth.'))
+    Somebody  tell the truth.
+
+    >>> print(simple_html_strip('What about<br/>\nmultiple lines?'))
+    What about
+    multiple lines?
+    """
+    html_stripper = re.compile('(<!--.*?-->)|(<[^>]*>)|([^<]+)', re.DOTALL)
+    texts = (match.group(3) or '' for match in html_stripper.finditer(s))
+    return ''.join(texts)
+
+
+class SeparatedValues(str):
+    """
+    A string separated by a separator. Overrides __iter__ for getting
+    the values.
+
+    >>> list(SeparatedValues('a,b,c'))
+    ['a', 'b', 'c']
+
+    Whitespace is stripped and empty values are discarded.
+
+    >>> list(SeparatedValues(' a,   b   , c,  '))
+    ['a', 'b', 'c']
+    """
+
+    separator = ','
+
+    def __iter__(self):
+        parts = self.split(self.separator)
+        return filter(None, (part.strip() for part in parts))
+
+
+class Stripper:
+    r"""
+    Given a series of lines, find the common prefix and strip it from them.
+
+    >>> lines = [
+    ...     'abcdefg\n',
+    ...     'abc\n',
+    ...     'abcde\n',
+    ... ]
+    >>> res = Stripper.strip_prefix(lines)
+    >>> res.prefix
+    'abc'
+    >>> list(res.lines)
+    ['defg\n', '\n', 'de\n']
+
+    If no prefix is common, nothing should be stripped.
+
+    >>> lines = [
+    ...     'abcd\n',
+    ...     '1234\n',
+    ... ]
+    >>> res = Stripper.strip_prefix(lines)
+    >>> res.prefix = ''
+    >>> list(res.lines)
+    ['abcd\n', '1234\n']
+    """
+
+    def __init__(self, prefix, lines):
+        self.prefix = prefix
+        self.lines = map(self, lines)
+
+    @classmethod
+    def strip_prefix(cls, lines):
+        prefix_lines, lines = itertools.tee(lines)
+        prefix = functools.reduce(cls.common_prefix, prefix_lines)
+        return cls(prefix, lines)
+
+    def __call__(self, line):
+        if not self.prefix:
+            return line
+        null, prefix, rest = line.partition(self.prefix)
+        return rest
+
+    @staticmethod
+    def common_prefix(s1, s2):
+        """
+        Return the common prefix of two lines.
+        """
+        index = min(len(s1), len(s2))
+        while s1[:index] != s2[:index]:
+            index -= 1
+        return s1[:index]
+
+
+def remove_prefix(text, prefix):
+    """
+    Remove the prefix from the text if it exists.
+
+    >>> remove_prefix('underwhelming performance', 'underwhelming ')
+    'performance'
+
+    >>> remove_prefix('something special', 'sample')
+    'something special'
+    """
+    null, prefix, rest = text.rpartition(prefix)
+    return rest
+
+
+def remove_suffix(text, suffix):
+    """
+    Remove the suffix from the text if it exists.
+
+    >>> remove_suffix('name.git', '.git')
+    'name'
+
+    >>> remove_suffix('something special', 'sample')
+    'something special'
+    """
+    rest, suffix, null = text.partition(suffix)
+    return rest
+
+
+def normalize_newlines(text):
+    r"""
+    Replace alternate newlines with the canonical newline.
+
+    >>> normalize_newlines('Lorem Ipsum\u2029')
+    'Lorem Ipsum\n'
+    >>> normalize_newlines('Lorem Ipsum\r\n')
+    'Lorem Ipsum\n'
+    >>> normalize_newlines('Lorem Ipsum\x85')
+    'Lorem Ipsum\n'
+    """
+    newlines = ['\r\n', '\r', '\n', '\u0085', '\u2028', '\u2029']
+    pattern = '|'.join(newlines)
+    return re.sub(pattern, '\n', text)
+
+
+def _nonblank(str):
+    return str and not str.startswith('#')
+
+
+@functools.singledispatch
+def yield_lines(iterable):
+    r"""
+    Yield valid lines of a string or iterable.
+
+    >>> list(yield_lines(''))
+    []
+    >>> list(yield_lines(['foo', 'bar']))
+    ['foo', 'bar']
+    >>> list(yield_lines('foo\nbar'))
+    ['foo', 'bar']
+    >>> list(yield_lines('\nfoo\n#bar\nbaz #comment'))
+    ['foo', 'baz #comment']
+    >>> list(yield_lines(['foo\nbar', 'baz', 'bing\n\n\n']))
+    ['foo', 'bar', 'baz', 'bing']
+    """
+    return itertools.chain.from_iterable(map(yield_lines, iterable))
+
+
+@yield_lines.register(str)
+def _(text):
+    return filter(_nonblank, map(str.strip, text.splitlines()))
+
+
+def drop_comment(line):
+    """
+    Drop comments.
+
+    >>> drop_comment('foo # bar')
+    'foo'
+
+    A hash without a space may be in a URL.
+
+    >>> drop_comment('http://example.com/foo#bar')
+    'http://example.com/foo#bar'
+    """
+    return line.partition(' #')[0]
+
+
+def join_continuation(lines):
+    r"""
+    Join lines continued by a trailing backslash.
+
+    >>> list(join_continuation(['foo \\', 'bar', 'baz']))
+    ['foobar', 'baz']
+    >>> list(join_continuation(['foo \\', 'bar', 'baz']))
+    ['foobar', 'baz']
+    >>> list(join_continuation(['foo \\', 'bar \\', 'baz']))
+    ['foobarbaz']
+
+    Not sure why, but...
+    The character preceeding the backslash is also elided.
+
+    >>> list(join_continuation(['goo\\', 'dly']))
+    ['godly']
+
+    A terrible idea, but...
+    If no line is available to continue, suppress the lines.
+
+    >>> list(join_continuation(['foo', 'bar\\', 'baz\\']))
+    ['foo']
+    """
+    lines = iter(lines)
+    for item in lines:
+        while item.endswith('\\'):
+            try:
+                item = item[:-2].strip() + next(lines)
+            except StopIteration:
+                return
+        yield item
diff --git a/third_party/python/setuptools/pkg_resources/_vendor/more_itertools/__init__.py b/third_party/python/setuptools/pkg_resources/_vendor/more_itertools/__init__.py
new file mode 100644
index 0000000000..66443971df
--- /dev/null
+++ b/third_party/python/setuptools/pkg_resources/_vendor/more_itertools/__init__.py
@@ -0,0 +1,6 @@
+"""More routines for operating on iterables, beyond itertools"""
+
+from .more import *  # noqa
+from .recipes import *  # noqa
+
+__version__ = '9.1.0'
diff --git a/third_party/python/setuptools/pkg_resources/_vendor/more_itertools/more.py b/third_party/python/setuptools/pkg_resources/_vendor/more_itertools/more.py
new file mode 100644
index 0000000000..e0e2d3de92
--- /dev/null
+++ b/third_party/python/setuptools/pkg_resources/_vendor/more_itertools/more.py
@@ -0,0 +1,4391 @@
+import warnings
+
+from collections import Counter, defaultdict, deque, abc
+from collections.abc import Sequence
+from functools import partial, reduce, wraps
+from heapq import heapify, heapreplace, heappop
+from itertools import (
+    chain,
+    compress,
+    count,
+    cycle,
+    dropwhile,
+    groupby,
+    islice,
+    repeat,
+    starmap,
+    takewhile,
+    tee,
+    zip_longest,
+)
+from math import exp, factorial, floor, log
+from queue import Empty, Queue
+from random import random, randrange, uniform
+from operator import itemgetter, mul, sub, gt, lt, ge, le
+from sys import hexversion, maxsize
+from time import monotonic
+
+from .recipes import (
+    _marker,
+    _zip_equal,
+    UnequalIterablesError,
+    consume,
+    flatten,
+    pairwise,
+    powerset,
+    take,
+    unique_everseen,
+    all_equal,
+)
+
+__all__ = [
+    'AbortThread',
+    'SequenceView',
+    'UnequalIterablesError',
+    'adjacent',
+    'all_unique',
+    'always_iterable',
+    'always_reversible',
+    'bucket',
+    'callback_iter',
+    'chunked',
+    'chunked_even',
+    'circular_shifts',
+    'collapse',
+    'combination_index',
+    'consecutive_groups',
+    'constrained_batches',
+    'consumer',
+    'count_cycle',
+    'countable',
+    'difference',
+    'distinct_combinations',
+    'distinct_permutations',
+    'distribute',
+    'divide',
+    'duplicates_everseen',
+    'duplicates_justseen',
+    'exactly_n',
+    'filter_except',
+    'first',
+    'gray_product',
+    'groupby_transform',
+    'ichunked',
+    'iequals',
+    'ilen',
+    'interleave',
+    'interleave_evenly',
+    'interleave_longest',
+    'intersperse',
+    'is_sorted',
+    'islice_extended',
+    'iterate',
+    'last',
+    'locate',
+    'longest_common_prefix',
+    'lstrip',
+    'make_decorator',
+    'map_except',
+    'map_if',
+    'map_reduce',
+    'mark_ends',
+    'minmax',
+    'nth_or_last',
+    'nth_permutation',
+    'nth_product',
+    'numeric_range',
+    'one',
+    'only',
+    'padded',
+    'partitions',
+    'peekable',
+    'permutation_index',
+    'product_index',
+    'raise_',
+    'repeat_each',
+    'repeat_last',
+    'replace',
+    'rlocate',
+    'rstrip',
+    'run_length',
+    'sample',
+    'seekable',
+    'set_partitions',
+    'side_effect',
+    'sliced',
+    'sort_together',
+    'split_after',
+    'split_at',
+    'split_before',
+    'split_into',
+    'split_when',
+    'spy',
+    'stagger',
+    'strip',
+    'strictly_n',
+    'substrings',
+    'substrings_indexes',
+    'time_limited',
+    'unique_in_window',
+    'unique_to_each',
+    'unzip',
+    'value_chain',
+    'windowed',
+    'windowed_complete',
+    'with_iter',
+    'zip_broadcast',
+    'zip_equal',
+    'zip_offset',
+]
+
+
+def chunked(iterable, n, strict=False):
+    """Break *iterable* into lists of length *n*:
+
+        >>> list(chunked([1, 2, 3, 4, 5, 6], 3))
+        [[1, 2, 3], [4, 5, 6]]
+
+    By the default, the last yielded list will have fewer than *n* elements
+    if the length of *iterable* is not divisible by *n*:
+
+        >>> list(chunked([1, 2, 3, 4, 5, 6, 7, 8], 3))
+        [[1, 2, 3], [4, 5, 6], [7, 8]]
+
+    To use a fill-in value instead, see the :func:`grouper` recipe.
+
+    If the length of *iterable* is not divisible by *n* and *strict* is
+    ``True``, then ``ValueError`` will be raised before the last
+    list is yielded.
+
+    """
+    iterator = iter(partial(take, n, iter(iterable)), [])
+    if strict:
+        if n is None:
+            raise ValueError('n must not be None when using strict mode.')
+
+        def ret():
+            for chunk in iterator:
+                if len(chunk) != n:
+                    raise ValueError('iterable is not divisible by n.')
+                yield chunk
+
+        return iter(ret())
+    else:
+        return iterator
+
+
+def first(iterable, default=_marker):
+    """Return the first item of *iterable*, or *default* if *iterable* is
+    empty.
+
+        >>> first([0, 1, 2, 3])
+        0
+        >>> first([], 'some default')
+        'some default'
+
+    If *default* is not provided and there are no items in the iterable,
+    raise ``ValueError``.
+
+    :func:`first` is useful when you have a generator of expensive-to-retrieve
+    values and want any arbitrary one. It is marginally shorter than
+    ``next(iter(iterable), default)``.
+
+    """
+    try:
+        return next(iter(iterable))
+    except StopIteration as e:
+        if default is _marker:
+            raise ValueError(
+                'first() was called on an empty iterable, and no '
+                'default value was provided.'
+            ) from e
+        return default
+
+
+def last(iterable, default=_marker):
+    """Return the last item of *iterable*, or *default* if *iterable* is
+    empty.
+
+        >>> last([0, 1, 2, 3])
+        3
+        >>> last([], 'some default')
+        'some default'
+
+    If *default* is not provided and there are no items in the iterable,
+    raise ``ValueError``.
+    """
+    try:
+        if isinstance(iterable, Sequence):
+            return iterable[-1]
+        # Work around https://bugs.python.org/issue38525
+        elif hasattr(iterable, '__reversed__') and (hexversion != 0x030800F0):
+            return next(reversed(iterable))
+        else:
+            return deque(iterable, maxlen=1)[-1]
+    except (IndexError, TypeError, StopIteration):
+        if default is _marker:
+            raise ValueError(
+                'last() was called on an empty iterable, and no default was '
+                'provided.'
+            )
+        return default
+
+
+def nth_or_last(iterable, n, default=_marker):
+    """Return the nth or the last item of *iterable*,
+    or *default* if *iterable* is empty.
+
+        >>> nth_or_last([0, 1, 2, 3], 2)
+        2
+        >>> nth_or_last([0, 1], 2)
+        1
+        >>> nth_or_last([], 0, 'some default')
+        'some default'
+
+    If *default* is not provided and there are no items in the iterable,
+    raise ``ValueError``.
+    """
+    return last(islice(iterable, n + 1), default=default)
+
+
+class peekable:
+    """Wrap an iterator to allow lookahead and prepending elements.
+
+    Call :meth:`peek` on the result to get the value that will be returned
+    by :func:`next`. This won't advance the iterator:
+
+        >>> p = peekable(['a', 'b'])
+        >>> p.peek()
+        'a'
+        >>> next(p)
+        'a'
+
+    Pass :meth:`peek` a default value to return that instead of raising
+    ``StopIteration`` when the iterator is exhausted.
+
+        >>> p = peekable([])
+        >>> p.peek('hi')
+        'hi'
+
+    peekables also offer a :meth:`prepend` method, which "inserts" items
+    at the head of the iterable:
+
+        >>> p = peekable([1, 2, 3])
+        >>> p.prepend(10, 11, 12)
+        >>> next(p)
+        10
+        >>> p.peek()
+        11
+        >>> list(p)
+        [11, 12, 1, 2, 3]
+
+    peekables can be indexed. Index 0 is the item that will be returned by
+    :func:`next`, index 1 is the item after that, and so on:
+    The values up to the given index will be cached.
+
+        >>> p = peekable(['a', 'b', 'c', 'd'])
+        >>> p[0]
+        'a'
+        >>> p[1]
+        'b'
+        >>> next(p)
+        'a'
+
+    Negative indexes are supported, but be aware that they will cache the
+    remaining items in the source iterator, which may require significant
+    storage.
+
+    To check whether a peekable is exhausted, check its truth value:
+
+        >>> p = peekable(['a', 'b'])
+        >>> if p:  # peekable has items
+        ...     list(p)
+        ['a', 'b']
+        >>> if not p:  # peekable is exhausted
+        ...     list(p)
+        []
+
+    """
+
+    def __init__(self, iterable):
+        self._it = iter(iterable)
+        self._cache = deque()
+
+    def __iter__(self):
+        return self
+
+    def __bool__(self):
+        try:
+            self.peek()
+        except StopIteration:
+            return False
+        return True
+
+    def peek(self, default=_marker):
+        """Return the item that will be next returned from ``next()``.
+
+        Return ``default`` if there are no items left. If ``default`` is not
+        provided, raise ``StopIteration``.
+
+        """
+        if not self._cache:
+            try:
+                self._cache.append(next(self._it))
+            except StopIteration:
+                if default is _marker:
+                    raise
+                return default
+        return self._cache[0]
+
+    def prepend(self, *items):
+        """Stack up items to be the next ones returned from ``next()`` or
+        ``self.peek()``. The items will be returned in
+        first in, first out order::
+
+            >>> p = peekable([1, 2, 3])
+            >>> p.prepend(10, 11, 12)
+            >>> next(p)
+            10
+            >>> list(p)
+            [11, 12, 1, 2, 3]
+
+        It is possible, by prepending items, to "resurrect" a peekable that
+        previously raised ``StopIteration``.
+
+            >>> p = peekable([])
+            >>> next(p)
+            Traceback (most recent call last):
+              ...
+            StopIteration
+            >>> p.prepend(1)
+            >>> next(p)
+            1
+            >>> next(p)
+            Traceback (most recent call last):
+              ...
+            StopIteration
+
+        """
+        self._cache.extendleft(reversed(items))
+
+    def __next__(self):
+        if self._cache:
+            return self._cache.popleft()
+
+        return next(self._it)
+
+    def _get_slice(self, index):
+        # Normalize the slice's arguments
+        step = 1 if (index.step is None) else index.step
+        if step > 0:
+            start = 0 if (index.start is None) else index.start
+            stop = maxsize if (index.stop is None) else index.stop
+        elif step < 0:
+            start = -1 if (index.start is None) else index.start
+            stop = (-maxsize - 1) if (index.stop is None) else index.stop
+        else:
+            raise ValueError('slice step cannot be zero')
+
+        # If either the start or stop index is negative, we'll need to cache
+        # the rest of the iterable in order to slice from the right side.
+        if (start < 0) or (stop < 0):
+            self._cache.extend(self._it)
+        # Otherwise we'll need to find the rightmost index and cache to that
+        # point.
+        else:
+            n = min(max(start, stop) + 1, maxsize)
+            cache_len = len(self._cache)
+            if n >= cache_len:
+                self._cache.extend(islice(self._it, n - cache_len))
+
+        return list(self._cache)[index]
+
+    def __getitem__(self, index):
+        if isinstance(index, slice):
+            return self._get_slice(index)
+
+        cache_len = len(self._cache)
+        if index < 0:
+            self._cache.extend(self._it)
+        elif index >= cache_len:
+            self._cache.extend(islice(self._it, index + 1 - cache_len))
+
+        return self._cache[index]
+
+
+def consumer(func):
+    """Decorator that automatically advances a PEP-342-style "reverse iterator"
+    to its first yield point so you don't have to call ``next()`` on it
+    manually.
+
+        >>> @consumer
+        ... def tally():
+        ...     i = 0
+        ...     while True:
+        ...         print('Thing number %s is %s.' % (i, (yield)))
+        ...         i += 1
+        ...
+        >>> t = tally()
+        >>> t.send('red')
+        Thing number 0 is red.
+        >>> t.send('fish')
+        Thing number 1 is fish.
+
+    Without the decorator, you would have to call ``next(t)`` before
+    ``t.send()`` could be used.
+
+    """
+
+    @wraps(func)
+    def wrapper(*args, **kwargs):
+        gen = func(*args, **kwargs)
+        next(gen)
+        return gen
+
+    return wrapper
+
+
+def ilen(iterable):
+    """Return the number of items in *iterable*.
+
+        >>> ilen(x for x in range(1000000) if x % 3 == 0)
+        333334
+
+    This consumes the iterable, so handle with care.
+
+    """
+    # This approach was selected because benchmarks showed it's likely the
+    # fastest of the known implementations at the time of writing.
+    # See GitHub tracker: #236, #230.
+    counter = count()
+    deque(zip(iterable, counter), maxlen=0)
+    return next(counter)
+
+
+def iterate(func, start):
+    """Return ``start``, ``func(start)``, ``func(func(start))``, ...
+
+    >>> from itertools import islice
+    >>> list(islice(iterate(lambda x: 2*x, 1), 10))
+    [1, 2, 4, 8, 16, 32, 64, 128, 256, 512]
+
+    """
+    while True:
+        yield start
+        start = func(start)
+
+
+def with_iter(context_manager):
+    """Wrap an iterable in a ``with`` statement, so it closes once exhausted.
+
+    For example, this will close the file when the iterator is exhausted::
+
+        upper_lines = (line.upper() for line in with_iter(open('foo')))
+
+    Any context manager which returns an iterable is a candidate for
+    ``with_iter``.
+
+    """
+    with context_manager as iterable:
+        yield from iterable
+
+
+def one(iterable, too_short=None, too_long=None):
+    """Return the first item from *iterable*, which is expected to contain only
+    that item. Raise an exception if *iterable* is empty or has more than one
+    item.
+
+    :func:`one` is useful for ensuring that an iterable contains only one item.
+    For example, it can be used to retrieve the result of a database query
+    that is expected to return a single row.
+
+    If *iterable* is empty, ``ValueError`` will be raised. You may specify a
+    different exception with the *too_short* keyword:
+
+        >>> it = []
+        >>> one(it)  # doctest: +IGNORE_EXCEPTION_DETAIL
+        Traceback (most recent call last):
+        ...
+        ValueError: too many items in iterable (expected 1)'
+        >>> too_short = IndexError('too few items')
+        >>> one(it, too_short=too_short)  # doctest: +IGNORE_EXCEPTION_DETAIL
+        Traceback (most recent call last):
+        ...
+        IndexError: too few items
+
+    Similarly, if *iterable* contains more than one item, ``ValueError`` will
+    be raised. You may specify a different exception with the *too_long*
+    keyword:
+
+        >>> it = ['too', 'many']
+        >>> one(it)  # doctest: +IGNORE_EXCEPTION_DETAIL
+        Traceback (most recent call last):
+        ...
+        ValueError: Expected exactly one item in iterable, but got 'too',
+        'many', and perhaps more.
+        >>> too_long = RuntimeError
+        >>> one(it, too_long=too_long)  # doctest: +IGNORE_EXCEPTION_DETAIL
+        Traceback (most recent call last):
+        ...
+        RuntimeError
+
+    Note that :func:`one` attempts to advance *iterable* twice to ensure there
+    is only one item. See :func:`spy` or :func:`peekable` to check iterable
+    contents less destructively.
+
+    """
+    it = iter(iterable)
+
+    try:
+        first_value = next(it)
+    except StopIteration as e:
+        raise (
+            too_short or ValueError('too few items in iterable (expected 1)')
+        ) from e
+
+    try:
+        second_value = next(it)
+    except StopIteration:
+        pass
+    else:
+        msg = (
+            'Expected exactly one item in iterable, but got {!r}, {!r}, '
+            'and perhaps more.'.format(first_value, second_value)
+        )
+        raise too_long or ValueError(msg)
+
+    return first_value
+
+
+def raise_(exception, *args):
+    raise exception(*args)
+
+
+def strictly_n(iterable, n, too_short=None, too_long=None):
+    """Validate that *iterable* has exactly *n* items and return them if
+    it does. If it has fewer than *n* items, call function *too_short*
+    with those items. If it has more than *n* items, call function
+    *too_long* with the first ``n + 1`` items.
+
+        >>> iterable = ['a', 'b', 'c', 'd']
+        >>> n = 4
+        >>> list(strictly_n(iterable, n))
+        ['a', 'b', 'c', 'd']
+
+    By default, *too_short* and *too_long* are functions that raise
+    ``ValueError``.
+
+        >>> list(strictly_n('ab', 3))  # doctest: +IGNORE_EXCEPTION_DETAIL
+        Traceback (most recent call last):
+        ...
+        ValueError: too few items in iterable (got 2)
+
+        >>> list(strictly_n('abc', 2))  # doctest: +IGNORE_EXCEPTION_DETAIL
+        Traceback (most recent call last):
+        ...
+        ValueError: too many items in iterable (got at least 3)
+
+    You can instead supply functions that do something else.
+    *too_short* will be called with the number of items in *iterable*.
+    *too_long* will be called with `n + 1`.
+
+        >>> def too_short(item_count):
+        ...     raise RuntimeError
+        >>> it = strictly_n('abcd', 6, too_short=too_short)
+        >>> list(it)  # doctest: +IGNORE_EXCEPTION_DETAIL
+        Traceback (most recent call last):
+        ...
+        RuntimeError
+
+        >>> def too_long(item_count):
+        ...     print('The boss is going to hear about this')
+        >>> it = strictly_n('abcdef', 4, too_long=too_long)
+        >>> list(it)
+        The boss is going to hear about this
+        ['a', 'b', 'c', 'd']
+
+    """
+    if too_short is None:
+        too_short = lambda item_count: raise_(
+            ValueError,
+            'Too few items in iterable (got {})'.format(item_count),
+        )
+
+    if too_long is None:
+        too_long = lambda item_count: raise_(
+            ValueError,
+            'Too many items in iterable (got at least {})'.format(item_count),
+        )
+
+    it = iter(iterable)
+    for i in range(n):
+        try:
+            item = next(it)
+        except StopIteration:
+            too_short(i)
+            return
+        else:
+            yield item
+
+    try:
+        next(it)
+    except StopIteration:
+        pass
+    else:
+        too_long(n + 1)
+
+
+def distinct_permutations(iterable, r=None):
+    """Yield successive distinct permutations of the elements in *iterable*.
+
+        >>> sorted(distinct_permutations([1, 0, 1]))
+        [(0, 1, 1), (1, 0, 1), (1, 1, 0)]
+
+    Equivalent to ``set(permutations(iterable))``, except duplicates are not
+    generated and thrown away. For larger input sequences this is much more
+    efficient.
+
+    Duplicate permutations arise when there are duplicated elements in the
+    input iterable. The number of items returned is
+    `n! / (x_1! * x_2! * ... * x_n!)`, where `n` is the total number of
+    items input, and each `x_i` is the count of a distinct item in the input
+    sequence.
+
+    If *r* is given, only the *r*-length permutations are yielded.
+
+        >>> sorted(distinct_permutations([1, 0, 1], r=2))
+        [(0, 1), (1, 0), (1, 1)]
+        >>> sorted(distinct_permutations(range(3), r=2))
+        [(0, 1), (0, 2), (1, 0), (1, 2), (2, 0), (2, 1)]
+
+    """
+
+    # Algorithm: https://w.wiki/Qai
+    def _full(A):
+        while True:
+            # Yield the permutation we have
+            yield tuple(A)
+
+            # Find the largest index i such that A[i] < A[i + 1]
+            for i in range(size - 2, -1, -1):
+                if A[i] < A[i + 1]:
+                    break
+            #  If no such index exists, this permutation is the last one
+            else:
+                return
+
+            # Find the largest index j greater than j such that A[i] < A[j]
+            for j in range(size - 1, i, -1):
+                if A[i] < A[j]:
+                    break
+
+            # Swap the value of A[i] with that of A[j], then reverse the
+            # sequence from A[i + 1] to form the new permutation
+            A[i], A[j] = A[j], A[i]
+            A[i + 1 :] = A[: i - size : -1]  # A[i + 1:][::-1]
+
+    # Algorithm: modified from the above
+    def _partial(A, r):
+        # Split A into the first r items and the last r items
+        head, tail = A[:r], A[r:]
+        right_head_indexes = range(r - 1, -1, -1)
+        left_tail_indexes = range(len(tail))
+
+        while True:
+            # Yield the permutation we have
+            yield tuple(head)
+
+            # Starting from the right, find the first index of the head with
+            # value smaller than the maximum value of the tail - call it i.
+            pivot = tail[-1]
+            for i in right_head_indexes:
+                if head[i] < pivot:
+                    break
+                pivot = head[i]
+            else:
+                return
+
+            # Starting from the left, find the first value of the tail
+            # with a value greater than head[i] and swap.
+            for j in left_tail_indexes:
+                if tail[j] > head[i]:
+                    head[i], tail[j] = tail[j], head[i]
+                    break
+            # If we didn't find one, start from the right and find the first
+            # index of the head with a value greater than head[i] and swap.
+            else:
+                for j in right_head_indexes:
+                    if head[j] > head[i]:
+                        head[i], head[j] = head[j], head[i]
+                        break
+
+            # Reverse head[i + 1:] and swap it with tail[:r - (i + 1)]
+            tail += head[: i - r : -1]  # head[i + 1:][::-1]
+            i += 1
+            head[i:], tail[:] = tail[: r - i], tail[r - i :]
+
+    items = sorted(iterable)
+
+    size = len(items)
+    if r is None:
+        r = size
+
+    if 0 < r <= size:
+        return _full(items) if (r == size) else _partial(items, r)
+
+    return iter(() if r else ((),))
+
+
+def intersperse(e, iterable, n=1):
+    """Intersperse filler element *e* among the items in *iterable*, leaving
+    *n* items between each filler element.
+
+        >>> list(intersperse('!', [1, 2, 3, 4, 5]))
+        [1, '!', 2, '!', 3, '!', 4, '!', 5]
+
+        >>> list(intersperse(None, [1, 2, 3, 4, 5], n=2))
+        [1, 2, None, 3, 4, None, 5]
+
+    """
+    if n == 0:
+        raise ValueError('n must be > 0')
+    elif n == 1:
+        # interleave(repeat(e), iterable) -> e, x_0, e, x_1, e, x_2...
+        # islice(..., 1, None) -> x_0, e, x_1, e, x_2...
+        return islice(interleave(repeat(e), iterable), 1, None)
+    else:
+        # interleave(filler, chunks) -> [e], [x_0, x_1], [e], [x_2, x_3]...
+        # islice(..., 1, None) -> [x_0, x_1], [e], [x_2, x_3]...
+        # flatten(...) -> x_0, x_1, e, x_2, x_3...
+        filler = repeat([e])
+        chunks = chunked(iterable, n)
+        return flatten(islice(interleave(filler, chunks), 1, None))
+
+
+def unique_to_each(*iterables):
+    """Return the elements from each of the input iterables that aren't in the
+    other input iterables.
+
+    For example, suppose you have a set of packages, each with a set of
+    dependencies::
+
+        {'pkg_1': {'A', 'B'}, 'pkg_2': {'B', 'C'}, 'pkg_3': {'B', 'D'}}
+
+    If you remove one package, which dependencies can also be removed?
+
+    If ``pkg_1`` is removed, then ``A`` is no longer necessary - it is not
+    associated with ``pkg_2`` or ``pkg_3``. Similarly, ``C`` is only needed for
+    ``pkg_2``, and ``D`` is only needed for ``pkg_3``::
+
+        >>> unique_to_each({'A', 'B'}, {'B', 'C'}, {'B', 'D'})
+        [['A'], ['C'], ['D']]
+
+    If there are duplicates in one input iterable that aren't in the others
+    they will be duplicated in the output. Input order is preserved::
+
+        >>> unique_to_each("mississippi", "missouri")
+        [['p', 'p'], ['o', 'u', 'r']]
+
+    It is assumed that the elements of each iterable are hashable.
+
+    """
+    pool = [list(it) for it in iterables]
+    counts = Counter(chain.from_iterable(map(set, pool)))
+    uniques = {element for element in counts if counts[element] == 1}
+    return [list(filter(uniques.__contains__, it)) for it in pool]
+
+
+def windowed(seq, n, fillvalue=None, step=1):
+    """Return a sliding window of width *n* over the given iterable.
+
+        >>> all_windows = windowed([1, 2, 3, 4, 5], 3)
+        >>> list(all_windows)
+        [(1, 2, 3), (2, 3, 4), (3, 4, 5)]
+
+    When the window is larger than the iterable, *fillvalue* is used in place
+    of missing values:
+
+        >>> list(windowed([1, 2, 3], 4))
+        [(1, 2, 3, None)]
+
+    Each window will advance in increments of *step*:
+
+        >>> list(windowed([1, 2, 3, 4, 5, 6], 3, fillvalue='!', step=2))
+        [(1, 2, 3), (3, 4, 5), (5, 6, '!')]
+
+    To slide into the iterable's items, use :func:`chain` to add filler items
+    to the left:
+
+        >>> iterable = [1, 2, 3, 4]
+        >>> n = 3
+        >>> padding = [None] * (n - 1)
+        >>> list(windowed(chain(padding, iterable), 3))
+        [(None, None, 1), (None, 1, 2), (1, 2, 3), (2, 3, 4)]
+    """
+    if n < 0:
+        raise ValueError('n must be >= 0')
+    if n == 0:
+        yield tuple()
+        return
+    if step < 1:
+        raise ValueError('step must be >= 1')
+
+    window = deque(maxlen=n)
+    i = n
+    for _ in map(window.append, seq):
+        i -= 1
+        if not i:
+            i = step
+            yield tuple(window)
+
+    size = len(window)
+    if size == 0:
+        return
+    elif size < n:
+        yield tuple(chain(window, repeat(fillvalue, n - size)))
+    elif 0 < i < min(step, n):
+        window += (fillvalue,) * i
+        yield tuple(window)
+
+
+def substrings(iterable):
+    """Yield all of the substrings of *iterable*.
+
+        >>> [''.join(s) for s in substrings('more')]
+        ['m', 'o', 'r', 'e', 'mo', 'or', 're', 'mor', 'ore', 'more']
+
+    Note that non-string iterables can also be subdivided.
+
+        >>> list(substrings([0, 1, 2]))
+        [(0,), (1,), (2,), (0, 1), (1, 2), (0, 1, 2)]
+
+    """
+    # The length-1 substrings
+    seq = []
+    for item in iter(iterable):
+        seq.append(item)
+        yield (item,)
+    seq = tuple(seq)
+    item_count = len(seq)
+
+    # And the rest
+    for n in range(2, item_count + 1):
+        for i in range(item_count - n + 1):
+            yield seq[i : i + n]
+
+
+def substrings_indexes(seq, reverse=False):
+    """Yield all substrings and their positions in *seq*
+
+    The items yielded will be a tuple of the form ``(substr, i, j)``, where
+    ``substr == seq[i:j]``.
+
+    This function only works for iterables that support slicing, such as
+    ``str`` objects.
+
+    >>> for item in substrings_indexes('more'):
+    ...    print(item)
+    ('m', 0, 1)
+    ('o', 1, 2)
+    ('r', 2, 3)
+    ('e', 3, 4)
+    ('mo', 0, 2)
+    ('or', 1, 3)
+    ('re', 2, 4)
+    ('mor', 0, 3)
+    ('ore', 1, 4)
+    ('more', 0, 4)
+
+    Set *reverse* to ``True`` to yield the same items in the opposite order.
+
+
+    """
+    r = range(1, len(seq) + 1)
+    if reverse:
+        r = reversed(r)
+    return (
+        (seq[i : i + L], i, i + L) for L in r for i in range(len(seq) - L + 1)
+    )
+
+
+class bucket:
+    """Wrap *iterable* and return an object that buckets it iterable into
+    child iterables based on a *key* function.
+
+        >>> iterable = ['a1', 'b1', 'c1', 'a2', 'b2', 'c2', 'b3']
+        >>> s = bucket(iterable, key=lambda x: x[0])  # Bucket by 1st character
+        >>> sorted(list(s))  # Get the keys
+        ['a', 'b', 'c']
+        >>> a_iterable = s['a']
+        >>> next(a_iterable)
+        'a1'
+        >>> next(a_iterable)
+        'a2'
+        >>> list(s['b'])
+        ['b1', 'b2', 'b3']
+
+    The original iterable will be advanced and its items will be cached until
+    they are used by the child iterables. This may require significant storage.
+
+    By default, attempting to select a bucket to which no items belong  will
+    exhaust the iterable and cache all values.
+    If you specify a *validator* function, selected buckets will instead be
+    checked against it.
+
+        >>> from itertools import count
+        >>> it = count(1, 2)  # Infinite sequence of odd numbers
+        >>> key = lambda x: x % 10  # Bucket by last digit
+        >>> validator = lambda x: x in {1, 3, 5, 7, 9}  # Odd digits only
+        >>> s = bucket(it, key=key, validator=validator)
+        >>> 2 in s
+        False
+        >>> list(s[2])
+        []
+
+    """
+
+    def __init__(self, iterable, key, validator=None):
+        self._it = iter(iterable)
+        self._key = key
+        self._cache = defaultdict(deque)
+        self._validator = validator or (lambda x: True)
+
+    def __contains__(self, value):
+        if not self._validator(value):
+            return False
+
+        try:
+            item = next(self[value])
+        except StopIteration:
+            return False
+        else:
+            self._cache[value].appendleft(item)
+
+        return True
+
+    def _get_values(self, value):
+        """
+        Helper to yield items from the parent iterator that match *value*.
+        Items that don't match are stored in the local cache as they
+        are encountered.
+        """
+        while True:
+            # If we've cached some items that match the target value, emit
+            # the first one and evict it from the cache.
+            if self._cache[value]:
+                yield self._cache[value].popleft()
+            # Otherwise we need to advance the parent iterator to search for
+            # a matching item, caching the rest.
+            else:
+                while True:
+                    try:
+                        item = next(self._it)
+                    except StopIteration:
+                        return
+                    item_value = self._key(item)
+                    if item_value == value:
+                        yield item
+                        break
+                    elif self._validator(item_value):
+                        self._cache[item_value].append(item)
+
+    def __iter__(self):
+        for item in self._it:
+            item_value = self._key(item)
+            if self._validator(item_value):
+                self._cache[item_value].append(item)
+
+        yield from self._cache.keys()
+
+    def __getitem__(self, value):
+        if not self._validator(value):
+            return iter(())
+
+        return self._get_values(value)
+
+
+def spy(iterable, n=1):
+    """Return a 2-tuple with a list containing the first *n* elements of
+    *iterable*, and an iterator with the same items as *iterable*.
+    This allows you to "look ahead" at the items in the iterable without
+    advancing it.
+
+    There is one item in the list by default:
+
+        >>> iterable = 'abcdefg'
+        >>> head, iterable = spy(iterable)
+        >>> head
+        ['a']
+        >>> list(iterable)
+        ['a', 'b', 'c', 'd', 'e', 'f', 'g']
+
+    You may use unpacking to retrieve items instead of lists:
+
+        >>> (head,), iterable = spy('abcdefg')
+        >>> head
+        'a'
+        >>> (first, second), iterable = spy('abcdefg', 2)
+        >>> first
+        'a'
+        >>> second
+        'b'
+
+    The number of items requested can be larger than the number of items in
+    the iterable:
+
+        >>> iterable = [1, 2, 3, 4, 5]
+        >>> head, iterable = spy(iterable, 10)
+        >>> head
+        [1, 2, 3, 4, 5]
+        >>> list(iterable)
+        [1, 2, 3, 4, 5]
+
+    """
+    it = iter(iterable)
+    head = take(n, it)
+
+    return head.copy(), chain(head, it)
+
+
+def interleave(*iterables):
+    """Return a new iterable yielding from each iterable in turn,
+    until the shortest is exhausted.
+
+        >>> list(interleave([1, 2, 3], [4, 5], [6, 7, 8]))
+        [1, 4, 6, 2, 5, 7]
+
+    For a version that doesn't terminate after the shortest iterable is
+    exhausted, see :func:`interleave_longest`.
+
+    """
+    return chain.from_iterable(zip(*iterables))
+
+
+def interleave_longest(*iterables):
+    """Return a new iterable yielding from each iterable in turn,
+    skipping any that are exhausted.
+
+        >>> list(interleave_longest([1, 2, 3], [4, 5], [6, 7, 8]))
+        [1, 4, 6, 2, 5, 7, 3, 8]
+
+    This function produces the same output as :func:`roundrobin`, but may
+    perform better for some inputs (in particular when the number of iterables
+    is large).
+
+    """
+    i = chain.from_iterable(zip_longest(*iterables, fillvalue=_marker))
+    return (x for x in i if x is not _marker)
+
+
+def interleave_evenly(iterables, lengths=None):
+    """
+    Interleave multiple iterables so that their elements are evenly distributed
+    throughout the output sequence.
+
+    >>> iterables = [1, 2, 3, 4, 5], ['a', 'b']
+    >>> list(interleave_evenly(iterables))
+    [1, 2, 'a', 3, 4, 'b', 5]
+
+    >>> iterables = [[1, 2, 3], [4, 5], [6, 7, 8]]
+    >>> list(interleave_evenly(iterables))
+    [1, 6, 4, 2, 7, 3, 8, 5]
+
+    This function requires iterables of known length. Iterables without
+    ``__len__()`` can be used by manually specifying lengths with *lengths*:
+
+    >>> from itertools import combinations, repeat
+    >>> iterables = [combinations(range(4), 2), ['a', 'b', 'c']]
+    >>> lengths = [4 * (4 - 1) // 2, 3]
+    >>> list(interleave_evenly(iterables, lengths=lengths))
+    [(0, 1), (0, 2), 'a', (0, 3), (1, 2), 'b', (1, 3), (2, 3), 'c']
+
+    Based on Bresenham's algorithm.
+    """
+    if lengths is None:
+        try:
+            lengths = [len(it) for it in iterables]
+        except TypeError:
+            raise ValueError(
+                'Iterable lengths could not be determined automatically. '
+                'Specify them with the lengths keyword.'
+            )
+    elif len(iterables) != len(lengths):
+        raise ValueError('Mismatching number of iterables and lengths.')
+
+    dims = len(lengths)
+
+    # sort iterables by length, descending
+    lengths_permute = sorted(
+        range(dims), key=lambda i: lengths[i], reverse=True
+    )
+    lengths_desc = [lengths[i] for i in lengths_permute]
+    iters_desc = [iter(iterables[i]) for i in lengths_permute]
+
+    # the longest iterable is the primary one (Bresenham: the longest
+    # distance along an axis)
+    delta_primary, deltas_secondary = lengths_desc[0], lengths_desc[1:]
+    iter_primary, iters_secondary = iters_desc[0], iters_desc[1:]
+    errors = [delta_primary // dims] * len(deltas_secondary)
+
+    to_yield = sum(lengths)
+    while to_yield:
+        yield next(iter_primary)
+        to_yield -= 1
+        # update errors for each secondary iterable
+        errors = [e - delta for e, delta in zip(errors, deltas_secondary)]
+
+        # those iterables for which the error is negative are yielded
+        # ("diagonal step" in Bresenham)
+        for i, e in enumerate(errors):
+            if e < 0:
+                yield next(iters_secondary[i])
+                to_yield -= 1
+                errors[i] += delta_primary
+
+
+def collapse(iterable, base_type=None, levels=None):
+    """Flatten an iterable with multiple levels of nesting (e.g., a list of
+    lists of tuples) into non-iterable types.
+
+        >>> iterable = [(1, 2), ([3, 4], [[5], [6]])]
+        >>> list(collapse(iterable))
+        [1, 2, 3, 4, 5, 6]
+
+    Binary and text strings are not considered iterable and
+    will not be collapsed.
+
+    To avoid collapsing other types, specify *base_type*:
+
+        >>> iterable = ['ab', ('cd', 'ef'), ['gh', 'ij']]
+        >>> list(collapse(iterable, base_type=tuple))
+        ['ab', ('cd', 'ef'), 'gh', 'ij']
+
+    Specify *levels* to stop flattening after a certain level:
+
+    >>> iterable = [('a', ['b']), ('c', ['d'])]
+    >>> list(collapse(iterable))  # Fully flattened
+    ['a', 'b', 'c', 'd']
+    >>> list(collapse(iterable, levels=1))  # Only one level flattened
+    ['a', ['b'], 'c', ['d']]
+
+    """
+
+    def walk(node, level):
+        if (
+            ((levels is not None) and (level > levels))
+            or isinstance(node, (str, bytes))
+            or ((base_type is not None) and isinstance(node, base_type))
+        ):
+            yield node
+            return
+
+        try:
+            tree = iter(node)
+        except TypeError:
+            yield node
+            return
+        else:
+            for child in tree:
+                yield from walk(child, level + 1)
+
+    yield from walk(iterable, 0)
+
+
+def side_effect(func, iterable, chunk_size=None, before=None, after=None):
+    """Invoke *func* on each item in *iterable* (or on each *chunk_size* group
+    of items) before yielding the item.
+
+    `func` must be a function that takes a single argument. Its return value
+    will be discarded.
+
+    *before* and *after* are optional functions that take no arguments. They
+    will be executed before iteration starts and after it ends, respectively.
+
+    `side_effect` can be used for logging, updating progress bars, or anything
+    that is not functionally "pure."
+
+    Emitting a status message:
+
+        >>> from more_itertools import consume
+        >>> func = lambda item: print('Received {}'.format(item))
+        >>> consume(side_effect(func, range(2)))
+        Received 0
+        Received 1
+
+    Operating on chunks of items:
+
+        >>> pair_sums = []
+        >>> func = lambda chunk: pair_sums.append(sum(chunk))
+        >>> list(side_effect(func, [0, 1, 2, 3, 4, 5], 2))
+        [0, 1, 2, 3, 4, 5]
+        >>> list(pair_sums)
+        [1, 5, 9]
+
+    Writing to a file-like object:
+
+        >>> from io import StringIO
+        >>> from more_itertools import consume
+        >>> f = StringIO()
+        >>> func = lambda x: print(x, file=f)
+        >>> before = lambda: print(u'HEADER', file=f)
+        >>> after = f.close
+        >>> it = [u'a', u'b', u'c']
+        >>> consume(side_effect(func, it, before=before, after=after))
+        >>> f.closed
+        True
+
+    """
+    try:
+        if before is not None:
+            before()
+
+        if chunk_size is None:
+            for item in iterable:
+                func(item)
+                yield item
+        else:
+            for chunk in chunked(iterable, chunk_size):
+                func(chunk)
+                yield from chunk
+    finally:
+        if after is not None:
+            after()
+
+
+def sliced(seq, n, strict=False):
+    """Yield slices of length *n* from the sequence *seq*.
+
+    >>> list(sliced((1, 2, 3, 4, 5, 6), 3))
+    [(1, 2, 3), (4, 5, 6)]
+
+    By the default, the last yielded slice will have fewer than *n* elements
+    if the length of *seq* is not divisible by *n*:
+
+    >>> list(sliced((1, 2, 3, 4, 5, 6, 7, 8), 3))
+    [(1, 2, 3), (4, 5, 6), (7, 8)]
+
+    If the length of *seq* is not divisible by *n* and *strict* is
+    ``True``, then ``ValueError`` will be raised before the last
+    slice is yielded.
+
+    This function will only work for iterables that support slicing.
+    For non-sliceable iterables, see :func:`chunked`.
+
+    """
+    iterator = takewhile(len, (seq[i : i + n] for i in count(0, n)))
+    if strict:
+
+        def ret():
+            for _slice in iterator:
+                if len(_slice) != n:
+                    raise ValueError("seq is not divisible by n.")
+                yield _slice
+
+        return iter(ret())
+    else:
+        return iterator
+
+
+def split_at(iterable, pred, maxsplit=-1, keep_separator=False):
+    """Yield lists of items from *iterable*, where each list is delimited by
+    an item where callable *pred* returns ``True``.
+
+        >>> list(split_at('abcdcba', lambda x: x == 'b'))
+        [['a'], ['c', 'd', 'c'], ['a']]
+
+        >>> list(split_at(range(10), lambda n: n % 2 == 1))
+        [[0], [2], [4], [6], [8], []]
+
+    At most *maxsplit* splits are done. If *maxsplit* is not specified or -1,
+    then there is no limit on the number of splits:
+
+        >>> list(split_at(range(10), lambda n: n % 2 == 1, maxsplit=2))
+        [[0], [2], [4, 5, 6, 7, 8, 9]]
+
+    By default, the delimiting items are not included in the output.
+    To include them, set *keep_separator* to ``True``.
+
+        >>> list(split_at('abcdcba', lambda x: x == 'b', keep_separator=True))
+        [['a'], ['b'], ['c', 'd', 'c'], ['b'], ['a']]
+
+    """
+    if maxsplit == 0:
+        yield list(iterable)
+        return
+
+    buf = []
+    it = iter(iterable)
+    for item in it:
+        if pred(item):
+            yield buf
+            if keep_separator:
+                yield [item]
+            if maxsplit == 1:
+                yield list(it)
+                return
+            buf = []
+            maxsplit -= 1
+        else:
+            buf.append(item)
+    yield buf
+
+
+def split_before(iterable, pred, maxsplit=-1):
+    """Yield lists of items from *iterable*, where each list ends just before
+    an item for which callable *pred* returns ``True``:
+
+        >>> list(split_before('OneTwo', lambda s: s.isupper()))
+        [['O', 'n', 'e'], ['T', 'w', 'o']]
+
+        >>> list(split_before(range(10), lambda n: n % 3 == 0))
+        [[0, 1, 2], [3, 4, 5], [6, 7, 8], [9]]
+
+    At most *maxsplit* splits are done. If *maxsplit* is not specified or -1,
+    then there is no limit on the number of splits:
+
+        >>> list(split_before(range(10), lambda n: n % 3 == 0, maxsplit=2))
+        [[0, 1, 2], [3, 4, 5], [6, 7, 8, 9]]
+    """
+    if maxsplit == 0:
+        yield list(iterable)
+        return
+
+    buf = []
+    it = iter(iterable)
+    for item in it:
+        if pred(item) and buf:
+            yield buf
+            if maxsplit == 1:
+                yield [item] + list(it)
+                return
+            buf = []
+            maxsplit -= 1
+        buf.append(item)
+    if buf:
+        yield buf
+
+
+def split_after(iterable, pred, maxsplit=-1):
+    """Yield lists of items from *iterable*, where each list ends with an
+    item where callable *pred* returns ``True``:
+
+        >>> list(split_after('one1two2', lambda s: s.isdigit()))
+        [['o', 'n', 'e', '1'], ['t', 'w', 'o', '2']]
+
+        >>> list(split_after(range(10), lambda n: n % 3 == 0))
+        [[0], [1, 2, 3], [4, 5, 6], [7, 8, 9]]
+
+    At most *maxsplit* splits are done. If *maxsplit* is not specified or -1,
+    then there is no limit on the number of splits:
+
+        >>> list(split_after(range(10), lambda n: n % 3 == 0, maxsplit=2))
+        [[0], [1, 2, 3], [4, 5, 6, 7, 8, 9]]
+
+    """
+    if maxsplit == 0:
+        yield list(iterable)
+        return
+
+    buf = []
+    it = iter(iterable)
+    for item in it:
+        buf.append(item)
+        if pred(item) and buf:
+            yield buf
+            if maxsplit == 1:
+                buf = list(it)
+                if buf:
+                    yield buf
+                return
+            buf = []
+            maxsplit -= 1
+    if buf:
+        yield buf
+
+
+def split_when(iterable, pred, maxsplit=-1):
+    """Split *iterable* into pieces based on the output of *pred*.
+    *pred* should be a function that takes successive pairs of items and
+    returns ``True`` if the iterable should be split in between them.
+
+    For example, to find runs of increasing numbers, split the iterable when
+    element ``i`` is larger than element ``i + 1``:
+
+        >>> list(split_when([1, 2, 3, 3, 2, 5, 2, 4, 2], lambda x, y: x > y))
+        [[1, 2, 3, 3], [2, 5], [2, 4], [2]]
+
+    At most *maxsplit* splits are done. If *maxsplit* is not specified or -1,
+    then there is no limit on the number of splits:
+
+        >>> list(split_when([1, 2, 3, 3, 2, 5, 2, 4, 2],
+        ...                 lambda x, y: x > y, maxsplit=2))
+        [[1, 2, 3, 3], [2, 5], [2, 4, 2]]
+
+    """
+    if maxsplit == 0:
+        yield list(iterable)
+        return
+
+    it = iter(iterable)
+    try:
+        cur_item = next(it)
+    except StopIteration:
+        return
+
+    buf = [cur_item]
+    for next_item in it:
+        if pred(cur_item, next_item):
+            yield buf
+            if maxsplit == 1:
+                yield [next_item] + list(it)
+                return
+            buf = []
+            maxsplit -= 1
+
+        buf.append(next_item)
+        cur_item = next_item
+
+    yield buf
+
+
+def split_into(iterable, sizes):
+    """Yield a list of sequential items from *iterable* of length 'n' for each
+    integer 'n' in *sizes*.
+
+        >>> list(split_into([1,2,3,4,5,6], [1,2,3]))
+        [[1], [2, 3], [4, 5, 6]]
+
+    If the sum of *sizes* is smaller than the length of *iterable*, then the
+    remaining items of *iterable* will not be returned.
+
+        >>> list(split_into([1,2,3,4,5,6], [2,3]))
+        [[1, 2], [3, 4, 5]]
+
+    If the sum of *sizes* is larger than the length of *iterable*, fewer items
+    will be returned in the iteration that overruns *iterable* and further
+    lists will be empty:
+
+        >>> list(split_into([1,2,3,4], [1,2,3,4]))
+        [[1], [2, 3], [4], []]
+
+    When a ``None`` object is encountered in *sizes*, the returned list will
+    contain items up to the end of *iterable* the same way that itertools.slice
+    does:
+
+        >>> list(split_into([1,2,3,4,5,6,7,8,9,0], [2,3,None]))
+        [[1, 2], [3, 4, 5], [6, 7, 8, 9, 0]]
+
+    :func:`split_into` can be useful for grouping a series of items where the
+    sizes of the groups are not uniform. An example would be where in a row
+    from a table, multiple columns represent elements of the same feature
+    (e.g. a point represented by x,y,z) but, the format is not the same for
+    all columns.
+    """
+    # convert the iterable argument into an iterator so its contents can
+    # be consumed by islice in case it is a generator
+    it = iter(iterable)
+
+    for size in sizes:
+        if size is None:
+            yield list(it)
+            return
+        else:
+            yield list(islice(it, size))
+
+
+def padded(iterable, fillvalue=None, n=None, next_multiple=False):
+    """Yield the elements from *iterable*, followed by *fillvalue*, such that
+    at least *n* items are emitted.
+
+        >>> list(padded([1, 2, 3], '?', 5))
+        [1, 2, 3, '?', '?']
+
+    If *next_multiple* is ``True``, *fillvalue* will be emitted until the
+    number of items emitted is a multiple of *n*::
+
+        >>> list(padded([1, 2, 3, 4], n=3, next_multiple=True))
+        [1, 2, 3, 4, None, None]
+
+    If *n* is ``None``, *fillvalue* will be emitted indefinitely.
+
+    """
+    it = iter(iterable)
+    if n is None:
+        yield from chain(it, repeat(fillvalue))
+    elif n < 1:
+        raise ValueError('n must be at least 1')
+    else:
+        item_count = 0
+        for item in it:
+            yield item
+            item_count += 1
+
+        remaining = (n - item_count) % n if next_multiple else n - item_count
+        for _ in range(remaining):
+            yield fillvalue
+
+
+def repeat_each(iterable, n=2):
+    """Repeat each element in *iterable* *n* times.
+
+    >>> list(repeat_each('ABC', 3))
+    ['A', 'A', 'A', 'B', 'B', 'B', 'C', 'C', 'C']
+    """
+    return chain.from_iterable(map(repeat, iterable, repeat(n)))
+
+
+def repeat_last(iterable, default=None):
+    """After the *iterable* is exhausted, keep yielding its last element.
+
+        >>> list(islice(repeat_last(range(3)), 5))
+        [0, 1, 2, 2, 2]
+
+    If the iterable is empty, yield *default* forever::
+
+        >>> list(islice(repeat_last(range(0), 42), 5))
+        [42, 42, 42, 42, 42]
+
+    """
+    item = _marker
+    for item in iterable:
+        yield item
+    final = default if item is _marker else item
+    yield from repeat(final)
+
+
+def distribute(n, iterable):
+    """Distribute the items from *iterable* among *n* smaller iterables.
+
+        >>> group_1, group_2 = distribute(2, [1, 2, 3, 4, 5, 6])
+        >>> list(group_1)
+        [1, 3, 5]
+        >>> list(group_2)
+        [2, 4, 6]
+
+    If the length of *iterable* is not evenly divisible by *n*, then the
+    length of the returned iterables will not be identical:
+
+        >>> children = distribute(3, [1, 2, 3, 4, 5, 6, 7])
+        >>> [list(c) for c in children]
+        [[1, 4, 7], [2, 5], [3, 6]]
+
+    If the length of *iterable* is smaller than *n*, then the last returned
+    iterables will be empty:
+
+        >>> children = distribute(5, [1, 2, 3])
+        >>> [list(c) for c in children]
+        [[1], [2], [3], [], []]
+
+    This function uses :func:`itertools.tee` and may require significant
+    storage. If you need the order items in the smaller iterables to match the
+    original iterable, see :func:`divide`.
+
+    """
+    if n < 1:
+        raise ValueError('n must be at least 1')
+
+    children = tee(iterable, n)
+    return [islice(it, index, None, n) for index, it in enumerate(children)]
+
+
+def stagger(iterable, offsets=(-1, 0, 1), longest=False, fillvalue=None):
+    """Yield tuples whose elements are offset from *iterable*.
+    The amount by which the `i`-th item in each tuple is offset is given by
+    the `i`-th item in *offsets*.
+
+        >>> list(stagger([0, 1, 2, 3]))
+        [(None, 0, 1), (0, 1, 2), (1, 2, 3)]
+        >>> list(stagger(range(8), offsets=(0, 2, 4)))
+        [(0, 2, 4), (1, 3, 5), (2, 4, 6), (3, 5, 7)]
+
+    By default, the sequence will end when the final element of a tuple is the
+    last item in the iterable. To continue until the first element of a tuple
+    is the last item in the iterable, set *longest* to ``True``::
+
+        >>> list(stagger([0, 1, 2, 3], longest=True))
+        [(None, 0, 1), (0, 1, 2), (1, 2, 3), (2, 3, None), (3, None, None)]
+
+    By default, ``None`` will be used to replace offsets beyond the end of the
+    sequence. Specify *fillvalue* to use some other value.
+
+    """
+    children = tee(iterable, len(offsets))
+
+    return zip_offset(
+        *children, offsets=offsets, longest=longest, fillvalue=fillvalue
+    )
+
+
+def zip_equal(*iterables):
+    """``zip`` the input *iterables* together, but raise
+    ``UnequalIterablesError`` if they aren't all the same length.
+
+        >>> it_1 = range(3)
+        >>> it_2 = iter('abc')
+        >>> list(zip_equal(it_1, it_2))
+        [(0, 'a'), (1, 'b'), (2, 'c')]
+
+        >>> it_1 = range(3)
+        >>> it_2 = iter('abcd')
+        >>> list(zip_equal(it_1, it_2)) # doctest: +IGNORE_EXCEPTION_DETAIL
+        Traceback (most recent call last):
+        ...
+        more_itertools.more.UnequalIterablesError: Iterables have different
+        lengths
+
+    """
+    if hexversion >= 0x30A00A6:
+        warnings.warn(
+            (
+                'zip_equal will be removed in a future version of '
+                'more-itertools. Use the builtin zip function with '
+                'strict=True instead.'
+            ),
+            DeprecationWarning,
+        )
+
+    return _zip_equal(*iterables)
+
+
+def zip_offset(*iterables, offsets, longest=False, fillvalue=None):
+    """``zip`` the input *iterables* together, but offset the `i`-th iterable
+    by the `i`-th item in *offsets*.
+
+        >>> list(zip_offset('0123', 'abcdef', offsets=(0, 1)))
+        [('0', 'b'), ('1', 'c'), ('2', 'd'), ('3', 'e')]
+
+    This can be used as a lightweight alternative to SciPy or pandas to analyze
+    data sets in which some series have a lead or lag relationship.
+
+    By default, the sequence will end when the shortest iterable is exhausted.
+    To continue until the longest iterable is exhausted, set *longest* to
+    ``True``.
+
+        >>> list(zip_offset('0123', 'abcdef', offsets=(0, 1), longest=True))
+        [('0', 'b'), ('1', 'c'), ('2', 'd'), ('3', 'e'), (None, 'f')]
+
+    By default, ``None`` will be used to replace offsets beyond the end of the
+    sequence. Specify *fillvalue* to use some other value.
+
+    """
+    if len(iterables) != len(offsets):
+        raise ValueError("Number of iterables and offsets didn't match")
+
+    staggered = []
+    for it, n in zip(iterables, offsets):
+        if n < 0:
+            staggered.append(chain(repeat(fillvalue, -n), it))
+        elif n > 0:
+            staggered.append(islice(it, n, None))
+        else:
+            staggered.append(it)
+
+    if longest:
+        return zip_longest(*staggered, fillvalue=fillvalue)
+
+    return zip(*staggered)
+
+
+def sort_together(iterables, key_list=(0,), key=None, reverse=False):
+    """Return the input iterables sorted together, with *key_list* as the
+    priority for sorting. All iterables are trimmed to the length of the
+    shortest one.
+
+    This can be used like the sorting function in a spreadsheet. If each
+    iterable represents a column of data, the key list determines which
+    columns are used for sorting.
+
+    By default, all iterables are sorted using the ``0``-th iterable::
+
+        >>> iterables = [(4, 3, 2, 1), ('a', 'b', 'c', 'd')]
+        >>> sort_together(iterables)
+        [(1, 2, 3, 4), ('d', 'c', 'b', 'a')]
+
+    Set a different key list to sort according to another iterable.
+    Specifying multiple keys dictates how ties are broken::
+
+        >>> iterables = [(3, 1, 2), (0, 1, 0), ('c', 'b', 'a')]
+        >>> sort_together(iterables, key_list=(1, 2))
+        [(2, 3, 1), (0, 0, 1), ('a', 'c', 'b')]
+
+    To sort by a function of the elements of the iterable, pass a *key*
+    function. Its arguments are the elements of the iterables corresponding to
+    the key list::
+
+        >>> names = ('a', 'b', 'c')
+        >>> lengths = (1, 2, 3)
+        >>> widths = (5, 2, 1)
+        >>> def area(length, width):
+        ...     return length * width
+        >>> sort_together([names, lengths, widths], key_list=(1, 2), key=area)
+        [('c', 'b', 'a'), (3, 2, 1), (1, 2, 5)]
+
+    Set *reverse* to ``True`` to sort in descending order.
+
+        >>> sort_together([(1, 2, 3), ('c', 'b', 'a')], reverse=True)
+        [(3, 2, 1), ('a', 'b', 'c')]
+
+    """
+    if key is None:
+        # if there is no key function, the key argument to sorted is an
+        # itemgetter
+        key_argument = itemgetter(*key_list)
+    else:
+        # if there is a key function, call it with the items at the offsets
+        # specified by the key function as arguments
+        key_list = list(key_list)
+        if len(key_list) == 1:
+            # if key_list contains a single item, pass the item at that offset
+            # as the only argument to the key function
+            key_offset = key_list[0]
+            key_argument = lambda zipped_items: key(zipped_items[key_offset])
+        else:
+            # if key_list contains multiple items, use itemgetter to return a
+            # tuple of items, which we pass as *args to the key function
+            get_key_items = itemgetter(*key_list)
+            key_argument = lambda zipped_items: key(
+                *get_key_items(zipped_items)
+            )
+
+    return list(
+        zip(*sorted(zip(*iterables), key=key_argument, reverse=reverse))
+    )
+
+
+def unzip(iterable):
+    """The inverse of :func:`zip`, this function disaggregates the elements
+    of the zipped *iterable*.
+
+    The ``i``-th iterable contains the ``i``-th element from each element
+    of the zipped iterable. The first element is used to determine the
+    length of the remaining elements.
+
+        >>> iterable = [('a', 1), ('b', 2), ('c', 3), ('d', 4)]
+        >>> letters, numbers = unzip(iterable)
+        >>> list(letters)
+        ['a', 'b', 'c', 'd']
+        >>> list(numbers)
+        [1, 2, 3, 4]
+
+    This is similar to using ``zip(*iterable)``, but it avoids reading
+    *iterable* into memory. Note, however, that this function uses
+    :func:`itertools.tee` and thus may require significant storage.
+
+    """
+    head, iterable = spy(iter(iterable))
+    if not head:
+        # empty iterable, e.g. zip([], [], [])
+        return ()
+    # spy returns a one-length iterable as head
+    head = head[0]
+    iterables = tee(iterable, len(head))
+
+    def itemgetter(i):
+        def getter(obj):
+            try:
+                return obj[i]
+            except IndexError:
+                # basically if we have an iterable like
+                # iter([(1, 2, 3), (4, 5), (6,)])
+                # the second unzipped iterable would fail at the third tuple
+                # since it would try to access tup[1]
+                # same with the third unzipped iterable and the second tuple
+                # to support these "improperly zipped" iterables,
+                # we create a custom itemgetter
+                # which just stops the unzipped iterables
+                # at first length mismatch
+                raise StopIteration
+
+        return getter
+
+    return tuple(map(itemgetter(i), it) for i, it in enumerate(iterables))
+
+
+def divide(n, iterable):
+    """Divide the elements from *iterable* into *n* parts, maintaining
+    order.
+
+        >>> group_1, group_2 = divide(2, [1, 2, 3, 4, 5, 6])
+        >>> list(group_1)
+        [1, 2, 3]
+        >>> list(group_2)
+        [4, 5, 6]
+
+    If the length of *iterable* is not evenly divisible by *n*, then the
+    length of the returned iterables will not be identical:
+
+        >>> children = divide(3, [1, 2, 3, 4, 5, 6, 7])
+        >>> [list(c) for c in children]
+        [[1, 2, 3], [4, 5], [6, 7]]
+
+    If the length of the iterable is smaller than n, then the last returned
+    iterables will be empty:
+
+        >>> children = divide(5, [1, 2, 3])
+        >>> [list(c) for c in children]
+        [[1], [2], [3], [], []]
+
+    This function will exhaust the iterable before returning and may require
+    significant storage. If order is not important, see :func:`distribute`,
+    which does not first pull the iterable into memory.
+
+    """
+    if n < 1:
+        raise ValueError('n must be at least 1')
+
+    try:
+        iterable[:0]
+    except TypeError:
+        seq = tuple(iterable)
+    else:
+        seq = iterable
+
+    q, r = divmod(len(seq), n)
+
+    ret = []
+    stop = 0
+    for i in range(1, n + 1):
+        start = stop
+        stop += q + 1 if i <= r else q
+        ret.append(iter(seq[start:stop]))
+
+    return ret
+
+
+def always_iterable(obj, base_type=(str, bytes)):
+    """If *obj* is iterable, return an iterator over its items::
+
+        >>> obj = (1, 2, 3)
+        >>> list(always_iterable(obj))
+        [1, 2, 3]
+
+    If *obj* is not iterable, return a one-item iterable containing *obj*::
+
+        >>> obj = 1
+        >>> list(always_iterable(obj))
+        [1]
+
+    If *obj* is ``None``, return an empty iterable:
+
+        >>> obj = None
+        >>> list(always_iterable(None))
+        []
+
+    By default, binary and text strings are not considered iterable::
+
+        >>> obj = 'foo'
+        >>> list(always_iterable(obj))
+        ['foo']
+
+    If *base_type* is set, objects for which ``isinstance(obj, base_type)``
+    returns ``True`` won't be considered iterable.
+
+        >>> obj = {'a': 1}
+        >>> list(always_iterable(obj))  # Iterate over the dict's keys
+        ['a']
+        >>> list(always_iterable(obj, base_type=dict))  # Treat dicts as a unit
+        [{'a': 1}]
+
+    Set *base_type* to ``None`` to avoid any special handling and treat objects
+    Python considers iterable as iterable:
+
+        >>> obj = 'foo'
+        >>> list(always_iterable(obj, base_type=None))
+        ['f', 'o', 'o']
+    """
+    if obj is None:
+        return iter(())
+
+    if (base_type is not None) and isinstance(obj, base_type):
+        return iter((obj,))
+
+    try:
+        return iter(obj)
+    except TypeError:
+        return iter((obj,))
+
+
+def adjacent(predicate, iterable, distance=1):
+    """Return an iterable over `(bool, item)` tuples where the `item` is
+    drawn from *iterable* and the `bool` indicates whether
+    that item satisfies the *predicate* or is adjacent to an item that does.
+
+    For example, to find whether items are adjacent to a ``3``::
+
+        >>> list(adjacent(lambda x: x == 3, range(6)))
+        [(False, 0), (False, 1), (True, 2), (True, 3), (True, 4), (False, 5)]
+
+    Set *distance* to change what counts as adjacent. For example, to find
+    whether items are two places away from a ``3``:
+
+        >>> list(adjacent(lambda x: x == 3, range(6), distance=2))
+        [(False, 0), (True, 1), (True, 2), (True, 3), (True, 4), (True, 5)]
+
+    This is useful for contextualizing the results of a search function.
+    For example, a code comparison tool might want to identify lines that
+    have changed, but also surrounding lines to give the viewer of the diff
+    context.
+
+    The predicate function will only be called once for each item in the
+    iterable.
+
+    See also :func:`groupby_transform`, which can be used with this function
+    to group ranges of items with the same `bool` value.
+
+    """
+    # Allow distance=0 mainly for testing that it reproduces results with map()
+    if distance < 0:
+        raise ValueError('distance must be at least 0')
+
+    i1, i2 = tee(iterable)
+    padding = [False] * distance
+    selected = chain(padding, map(predicate, i1), padding)
+    adjacent_to_selected = map(any, windowed(selected, 2 * distance + 1))
+    return zip(adjacent_to_selected, i2)
+
+
+def groupby_transform(iterable, keyfunc=None, valuefunc=None, reducefunc=None):
+    """An extension of :func:`itertools.groupby` that can apply transformations
+    to the grouped data.
+
+    * *keyfunc* is a function computing a key value for each item in *iterable*
+    * *valuefunc* is a function that transforms the individual items from
+      *iterable* after grouping
+    * *reducefunc* is a function that transforms each group of items
+
+    >>> iterable = 'aAAbBBcCC'
+    >>> keyfunc = lambda k: k.upper()
+    >>> valuefunc = lambda v: v.lower()
+    >>> reducefunc = lambda g: ''.join(g)
+    >>> list(groupby_transform(iterable, keyfunc, valuefunc, reducefunc))
+    [('A', 'aaa'), ('B', 'bbb'), ('C', 'ccc')]
+
+    Each optional argument defaults to an identity function if not specified.
+
+    :func:`groupby_transform` is useful when grouping elements of an iterable
+    using a separate iterable as the key. To do this, :func:`zip` the iterables
+    and pass a *keyfunc* that extracts the first element and a *valuefunc*
+    that extracts the second element::
+
+        >>> from operator import itemgetter
+        >>> keys = [0, 0, 1, 1, 1, 2, 2, 2, 3]
+        >>> values = 'abcdefghi'
+        >>> iterable = zip(keys, values)
+        >>> grouper = groupby_transform(iterable, itemgetter(0), itemgetter(1))
+        >>> [(k, ''.join(g)) for k, g in grouper]
+        [(0, 'ab'), (1, 'cde'), (2, 'fgh'), (3, 'i')]
+
+    Note that the order of items in the iterable is significant.
+    Only adjacent items are grouped together, so if you don't want any
+    duplicate groups, you should sort the iterable by the key function.
+
+    """
+    ret = groupby(iterable, keyfunc)
+    if valuefunc:
+        ret = ((k, map(valuefunc, g)) for k, g in ret)
+    if reducefunc:
+        ret = ((k, reducefunc(g)) for k, g in ret)
+
+    return ret
+
+
+class numeric_range(abc.Sequence, abc.Hashable):
+    """An extension of the built-in ``range()`` function whose arguments can
+    be any orderable numeric type.
+
+    With only *stop* specified, *start* defaults to ``0`` and *step*
+    defaults to ``1``. The output items will match the type of *stop*:
+
+        >>> list(numeric_range(3.5))
+        [0.0, 1.0, 2.0, 3.0]
+
+    With only *start* and *stop* specified, *step* defaults to ``1``. The
+    output items will match the type of *start*:
+
+        >>> from decimal import Decimal
+        >>> start = Decimal('2.1')
+        >>> stop = Decimal('5.1')
+        >>> list(numeric_range(start, stop))
+        [Decimal('2.1'), Decimal('3.1'), Decimal('4.1')]
+
+    With *start*, *stop*, and *step*  specified the output items will match
+    the type of ``start + step``:
+
+        >>> from fractions import Fraction
+        >>> start = Fraction(1, 2)  # Start at 1/2
+        >>> stop = Fraction(5, 2)  # End at 5/2
+        >>> step = Fraction(1, 2)  # Count by 1/2
+        >>> list(numeric_range(start, stop, step))
+        [Fraction(1, 2), Fraction(1, 1), Fraction(3, 2), Fraction(2, 1)]
+
+    If *step* is zero, ``ValueError`` is raised. Negative steps are supported:
+
+        >>> list(numeric_range(3, -1, -1.0))
+        [3.0, 2.0, 1.0, 0.0]
+
+    Be aware of the limitations of floating point numbers; the representation
+    of the yielded numbers may be surprising.
+
+    ``datetime.datetime`` objects can be used for *start* and *stop*, if *step*
+    is a ``datetime.timedelta`` object:
+
+        >>> import datetime
+        >>> start = datetime.datetime(2019, 1, 1)
+        >>> stop = datetime.datetime(2019, 1, 3)
+        >>> step = datetime.timedelta(days=1)
+        >>> items = iter(numeric_range(start, stop, step))
+        >>> next(items)
+        datetime.datetime(2019, 1, 1, 0, 0)
+        >>> next(items)
+        datetime.datetime(2019, 1, 2, 0, 0)
+
+    """
+
+    _EMPTY_HASH = hash(range(0, 0))
+
+    def __init__(self, *args):
+        argc = len(args)
+        if argc == 1:
+            (self._stop,) = args
+            self._start = type(self._stop)(0)
+            self._step = type(self._stop - self._start)(1)
+        elif argc == 2:
+            self._start, self._stop = args
+            self._step = type(self._stop - self._start)(1)
+        elif argc == 3:
+            self._start, self._stop, self._step = args
+        elif argc == 0:
+            raise TypeError(
+                'numeric_range expected at least '
+                '1 argument, got {}'.format(argc)
+            )
+        else:
+            raise TypeError(
+                'numeric_range expected at most '
+                '3 arguments, got {}'.format(argc)
+            )
+
+        self._zero = type(self._step)(0)
+        if self._step == self._zero:
+            raise ValueError('numeric_range() arg 3 must not be zero')
+        self._growing = self._step > self._zero
+        self._init_len()
+
+    def __bool__(self):
+        if self._growing:
+            return self._start < self._stop
+        else:
+            return self._start > self._stop
+
+    def __contains__(self, elem):
+        if self._growing:
+            if self._start <= elem < self._stop:
+                return (elem - self._start) % self._step == self._zero
+        else:
+            if self._start >= elem > self._stop:
+                return (self._start - elem) % (-self._step) == self._zero
+
+        return False
+
+    def __eq__(self, other):
+        if isinstance(other, numeric_range):
+            empty_self = not bool(self)
+            empty_other = not bool(other)
+            if empty_self or empty_other:
+                return empty_self and empty_other  # True if both empty
+            else:
+                return (
+                    self._start == other._start
+                    and self._step == other._step
+                    and self._get_by_index(-1) == other._get_by_index(-1)
+                )
+        else:
+            return False
+
+    def __getitem__(self, key):
+        if isinstance(key, int):
+            return self._get_by_index(key)
+        elif isinstance(key, slice):
+            step = self._step if key.step is None else key.step * self._step
+
+            if key.start is None or key.start <= -self._len:
+                start = self._start
+            elif key.start >= self._len:
+                start = self._stop
+            else:  # -self._len < key.start < self._len
+                start = self._get_by_index(key.start)
+
+            if key.stop is None or key.stop >= self._len:
+                stop = self._stop
+            elif key.stop <= -self._len:
+                stop = self._start
+            else:  # -self._len < key.stop < self._len
+                stop = self._get_by_index(key.stop)
+
+            return numeric_range(start, stop, step)
+        else:
+            raise TypeError(
+                'numeric range indices must be '
+                'integers or slices, not {}'.format(type(key).__name__)
+            )
+
+    def __hash__(self):
+        if self:
+            return hash((self._start, self._get_by_index(-1), self._step))
+        else:
+            return self._EMPTY_HASH
+
+    def __iter__(self):
+        values = (self._start + (n * self._step) for n in count())
+        if self._growing:
+            return takewhile(partial(gt, self._stop), values)
+        else:
+            return takewhile(partial(lt, self._stop), values)
+
+    def __len__(self):
+        return self._len
+
+    def _init_len(self):
+        if self._growing:
+            start = self._start
+            stop = self._stop
+            step = self._step
+        else:
+            start = self._stop
+            stop = self._start
+            step = -self._step
+        distance = stop - start
+        if distance <= self._zero:
+            self._len = 0
+        else:  # distance > 0 and step > 0: regular euclidean division
+            q, r = divmod(distance, step)
+            self._len = int(q) + int(r != self._zero)
+
+    def __reduce__(self):
+        return numeric_range, (self._start, self._stop, self._step)
+
+    def __repr__(self):
+        if self._step == 1:
+            return "numeric_range({}, {})".format(
+                repr(self._start), repr(self._stop)
+            )
+        else:
+            return "numeric_range({}, {}, {})".format(
+                repr(self._start), repr(self._stop), repr(self._step)
+            )
+
+    def __reversed__(self):
+        return iter(
+            numeric_range(
+                self._get_by_index(-1), self._start - self._step, -self._step
+            )
+        )
+
+    def count(self, value):
+        return int(value in self)
+
+    def index(self, value):
+        if self._growing:
+            if self._start <= value < self._stop:
+                q, r = divmod(value - self._start, self._step)
+                if r == self._zero:
+                    return int(q)
+        else:
+            if self._start >= value > self._stop:
+                q, r = divmod(self._start - value, -self._step)
+                if r == self._zero:
+                    return int(q)
+
+        raise ValueError("{} is not in numeric range".format(value))
+
+    def _get_by_index(self, i):
+        if i < 0:
+            i += self._len
+        if i < 0 or i >= self._len:
+            raise IndexError("numeric range object index out of range")
+        return self._start + i * self._step
+
+
+def count_cycle(iterable, n=None):
+    """Cycle through the items from *iterable* up to *n* times, yielding
+    the number of completed cycles along with each item. If *n* is omitted the
+    process repeats indefinitely.
+
+    >>> list(count_cycle('AB', 3))
+    [(0, 'A'), (0, 'B'), (1, 'A'), (1, 'B'), (2, 'A'), (2, 'B')]
+
+    """
+    iterable = tuple(iterable)
+    if not iterable:
+        return iter(())
+    counter = count() if n is None else range(n)
+    return ((i, item) for i in counter for item in iterable)
+
+
+def mark_ends(iterable):
+    """Yield 3-tuples of the form ``(is_first, is_last, item)``.
+
+    >>> list(mark_ends('ABC'))
+    [(True, False, 'A'), (False, False, 'B'), (False, True, 'C')]
+
+    Use this when looping over an iterable to take special action on its first
+    and/or last items:
+
+    >>> iterable = ['Header', 100, 200, 'Footer']
+    >>> total = 0
+    >>> for is_first, is_last, item in mark_ends(iterable):
+    ...     if is_first:
+    ...         continue  # Skip the header
+    ...     if is_last:
+    ...         continue  # Skip the footer
+    ...     total += item
+    >>> print(total)
+    300
+    """
+    it = iter(iterable)
+
+    try:
+        b = next(it)
+    except StopIteration:
+        return
+
+    try:
+        for i in count():
+            a = b
+            b = next(it)
+            yield i == 0, False, a
+
+    except StopIteration:
+        yield i == 0, True, a
+
+
+def locate(iterable, pred=bool, window_size=None):
+    """Yield the index of each item in *iterable* for which *pred* returns
+    ``True``.
+
+    *pred* defaults to :func:`bool`, which will select truthy items:
+
+        >>> list(locate([0, 1, 1, 0, 1, 0, 0]))
+        [1, 2, 4]
+
+    Set *pred* to a custom function to, e.g., find the indexes for a particular
+    item.
+
+        >>> list(locate(['a', 'b', 'c', 'b'], lambda x: x == 'b'))
+        [1, 3]
+
+    If *window_size* is given, then the *pred* function will be called with
+    that many items. This enables searching for sub-sequences:
+
+        >>> iterable = [0, 1, 2, 3, 0, 1, 2, 3, 0, 1, 2, 3]
+        >>> pred = lambda *args: args == (1, 2, 3)
+        >>> list(locate(iterable, pred=pred, window_size=3))
+        [1, 5, 9]
+
+    Use with :func:`seekable` to find indexes and then retrieve the associated
+    items:
+
+        >>> from itertools import count
+        >>> from more_itertools import seekable
+        >>> source = (3 * n + 1 if (n % 2) else n // 2 for n in count())
+        >>> it = seekable(source)
+        >>> pred = lambda x: x > 100
+        >>> indexes = locate(it, pred=pred)
+        >>> i = next(indexes)
+        >>> it.seek(i)
+        >>> next(it)
+        106
+
+    """
+    if window_size is None:
+        return compress(count(), map(pred, iterable))
+
+    if window_size < 1:
+        raise ValueError('window size must be at least 1')
+
+    it = windowed(iterable, window_size, fillvalue=_marker)
+    return compress(count(), starmap(pred, it))
+
+
+def longest_common_prefix(iterables):
+    """Yield elements of the longest common prefix amongst given *iterables*.
+
+    >>> ''.join(longest_common_prefix(['abcd', 'abc', 'abf']))
+    'ab'
+
+    """
+    return (c[0] for c in takewhile(all_equal, zip(*iterables)))
+
+
+def lstrip(iterable, pred):
+    """Yield the items from *iterable*, but strip any from the beginning
+    for which *pred* returns ``True``.
+
+    For example, to remove a set of items from the start of an iterable:
+
+        >>> iterable = (None, False, None, 1, 2, None, 3, False, None)
+        >>> pred = lambda x: x in {None, False, ''}
+        >>> list(lstrip(iterable, pred))
+        [1, 2, None, 3, False, None]
+
+    This function is analogous to to :func:`str.lstrip`, and is essentially
+    an wrapper for :func:`itertools.dropwhile`.
+
+    """
+    return dropwhile(pred, iterable)
+
+
+def rstrip(iterable, pred):
+    """Yield the items from *iterable*, but strip any from the end
+    for which *pred* returns ``True``.
+
+    For example, to remove a set of items from the end of an iterable:
+
+        >>> iterable = (None, False, None, 1, 2, None, 3, False, None)
+        >>> pred = lambda x: x in {None, False, ''}
+        >>> list(rstrip(iterable, pred))
+        [None, False, None, 1, 2, None, 3]
+
+    This function is analogous to :func:`str.rstrip`.
+
+    """
+    cache = []
+    cache_append = cache.append
+    cache_clear = cache.clear
+    for x in iterable:
+        if pred(x):
+            cache_append(x)
+        else:
+            yield from cache
+            cache_clear()
+            yield x
+
+
+def strip(iterable, pred):
+    """Yield the items from *iterable*, but strip any from the
+    beginning and end for which *pred* returns ``True``.
+
+    For example, to remove a set of items from both ends of an iterable:
+
+        >>> iterable = (None, False, None, 1, 2, None, 3, False, None)
+        >>> pred = lambda x: x in {None, False, ''}
+        >>> list(strip(iterable, pred))
+        [1, 2, None, 3]
+
+    This function is analogous to :func:`str.strip`.
+
+    """
+    return rstrip(lstrip(iterable, pred), pred)
+
+
+class islice_extended:
+    """An extension of :func:`itertools.islice` that supports negative values
+    for *stop*, *start*, and *step*.
+
+        >>> iterable = iter('abcdefgh')
+        >>> list(islice_extended(iterable, -4, -1))
+        ['e', 'f', 'g']
+
+    Slices with negative values require some caching of *iterable*, but this
+    function takes care to minimize the amount of memory required.
+
+    For example, you can use a negative step with an infinite iterator:
+
+        >>> from itertools import count
+        >>> list(islice_extended(count(), 110, 99, -2))
+        [110, 108, 106, 104, 102, 100]
+
+    You can also use slice notation directly:
+
+        >>> iterable = map(str, count())
+        >>> it = islice_extended(iterable)[10:20:2]
+        >>> list(it)
+        ['10', '12', '14', '16', '18']
+
+    """
+
+    def __init__(self, iterable, *args):
+        it = iter(iterable)
+        if args:
+            self._iterable = _islice_helper(it, slice(*args))
+        else:
+            self._iterable = it
+
+    def __iter__(self):
+        return self
+
+    def __next__(self):
+        return next(self._iterable)
+
+    def __getitem__(self, key):
+        if isinstance(key, slice):
+            return islice_extended(_islice_helper(self._iterable, key))
+
+        raise TypeError('islice_extended.__getitem__ argument must be a slice')
+
+
+def _islice_helper(it, s):
+    start = s.start
+    stop = s.stop
+    if s.step == 0:
+        raise ValueError('step argument must be a non-zero integer or None.')
+    step = s.step or 1
+
+    if step > 0:
+        start = 0 if (start is None) else start
+
+        if start < 0:
+            # Consume all but the last -start items
+            cache = deque(enumerate(it, 1), maxlen=-start)
+            len_iter = cache[-1][0] if cache else 0
+
+            # Adjust start to be positive
+            i = max(len_iter + start, 0)
+
+            # Adjust stop to be positive
+            if stop is None:
+                j = len_iter
+            elif stop >= 0:
+                j = min(stop, len_iter)
+            else:
+                j = max(len_iter + stop, 0)
+
+            # Slice the cache
+            n = j - i
+            if n <= 0:
+                return
+
+            for index, item in islice(cache, 0, n, step):
+                yield item
+        elif (stop is not None) and (stop < 0):
+            # Advance to the start position
+            next(islice(it, start, start), None)
+
+            # When stop is negative, we have to carry -stop items while
+            # iterating
+            cache = deque(islice(it, -stop), maxlen=-stop)
+
+            for index, item in enumerate(it):
+                cached_item = cache.popleft()
+                if index % step == 0:
+                    yield cached_item
+                cache.append(item)
+        else:
+            # When both start and stop are positive we have the normal case
+            yield from islice(it, start, stop, step)
+    else:
+        start = -1 if (start is None) else start
+
+        if (stop is not None) and (stop < 0):
+            # Consume all but the last items
+            n = -stop - 1
+            cache = deque(enumerate(it, 1), maxlen=n)
+            len_iter = cache[-1][0] if cache else 0
+
+            # If start and stop are both negative they are comparable and
+            # we can just slice. Otherwise we can adjust start to be negative
+            # and then slice.
+            if start < 0:
+                i, j = start, stop
+            else:
+                i, j = min(start - len_iter, -1), None
+
+            for index, item in list(cache)[i:j:step]:
+                yield item
+        else:
+            # Advance to the stop position
+            if stop is not None:
+                m = stop + 1
+                next(islice(it, m, m), None)
+
+            # stop is positive, so if start is negative they are not comparable
+            # and we need the rest of the items.
+            if start < 0:
+                i = start
+                n = None
+            # stop is None and start is positive, so we just need items up to
+            # the start index.
+            elif stop is None:
+                i = None
+                n = start + 1
+            # Both stop and start are positive, so they are comparable.
+            else:
+                i = None
+                n = start - stop
+                if n <= 0:
+                    return
+
+            cache = list(islice(it, n))
+
+            yield from cache[i::step]
+
+
+def always_reversible(iterable):
+    """An extension of :func:`reversed` that supports all iterables, not
+    just those which implement the ``Reversible`` or ``Sequence`` protocols.
+
+        >>> print(*always_reversible(x for x in range(3)))
+        2 1 0
+
+    If the iterable is already reversible, this function returns the
+    result of :func:`reversed()`. If the iterable is not reversible,
+    this function will cache the remaining items in the iterable and
+    yield them in reverse order, which may require significant storage.
+    """
+    try:
+        return reversed(iterable)
+    except TypeError:
+        return reversed(list(iterable))
+
+
+def consecutive_groups(iterable, ordering=lambda x: x):
+    """Yield groups of consecutive items using :func:`itertools.groupby`.
+    The *ordering* function determines whether two items are adjacent by
+    returning their position.
+
+    By default, the ordering function is the identity function. This is
+    suitable for finding runs of numbers:
+
+        >>> iterable = [1, 10, 11, 12, 20, 30, 31, 32, 33, 40]
+        >>> for group in consecutive_groups(iterable):
+        ...     print(list(group))
+        [1]
+        [10, 11, 12]
+        [20]
+        [30, 31, 32, 33]
+        [40]
+
+    For finding runs of adjacent letters, try using the :meth:`index` method
+    of a string of letters:
+
+        >>> from string import ascii_lowercase
+        >>> iterable = 'abcdfgilmnop'
+        >>> ordering = ascii_lowercase.index
+        >>> for group in consecutive_groups(iterable, ordering):
+        ...     print(list(group))
+        ['a', 'b', 'c', 'd']
+        ['f', 'g']
+        ['i']
+        ['l', 'm', 'n', 'o', 'p']
+
+    Each group of consecutive items is an iterator that shares it source with
+    *iterable*. When an an output group is advanced, the previous group is
+    no longer available unless its elements are copied (e.g., into a ``list``).
+
+        >>> iterable = [1, 2, 11, 12, 21, 22]
+        >>> saved_groups = []
+        >>> for group in consecutive_groups(iterable):
+        ...     saved_groups.append(list(group))  # Copy group elements
+        >>> saved_groups
+        [[1, 2], [11, 12], [21, 22]]
+
+    """
+    for k, g in groupby(
+        enumerate(iterable), key=lambda x: x[0] - ordering(x[1])
+    ):
+        yield map(itemgetter(1), g)
+
+
+def difference(iterable, func=sub, *, initial=None):
+    """This function is the inverse of :func:`itertools.accumulate`. By default
+    it will compute the first difference of *iterable* using
+    :func:`operator.sub`:
+
+        >>> from itertools import accumulate
+        >>> iterable = accumulate([0, 1, 2, 3, 4])  # produces 0, 1, 3, 6, 10
+        >>> list(difference(iterable))
+        [0, 1, 2, 3, 4]
+
+    *func* defaults to :func:`operator.sub`, but other functions can be
+    specified. They will be applied as follows::
+
+        A, B, C, D, ... --> A, func(B, A), func(C, B), func(D, C), ...
+
+    For example, to do progressive division:
+
+        >>> iterable = [1, 2, 6, 24, 120]
+        >>> func = lambda x, y: x // y
+        >>> list(difference(iterable, func))
+        [1, 2, 3, 4, 5]
+
+    If the *initial* keyword is set, the first element will be skipped when
+    computing successive differences.
+
+        >>> it = [10, 11, 13, 16]  # from accumulate([1, 2, 3], initial=10)
+        >>> list(difference(it, initial=10))
+        [1, 2, 3]
+
+    """
+    a, b = tee(iterable)
+    try:
+        first = [next(b)]
+    except StopIteration:
+        return iter([])
+
+    if initial is not None:
+        first = []
+
+    return chain(first, map(func, b, a))
+
+
+class SequenceView(Sequence):
+    """Return a read-only view of the sequence object *target*.
+
+    :class:`SequenceView` objects are analogous to Python's built-in
+    "dictionary view" types. They provide a dynamic view of a sequence's items,
+    meaning that when the sequence updates, so does the view.
+
+        >>> seq = ['0', '1', '2']
+        >>> view = SequenceView(seq)
+        >>> view
+        SequenceView(['0', '1', '2'])
+        >>> seq.append('3')
+        >>> view
+        SequenceView(['0', '1', '2', '3'])
+
+    Sequence views support indexing, slicing, and length queries. They act
+    like the underlying sequence, except they don't allow assignment:
+
+        >>> view[1]
+        '1'
+        >>> view[1:-1]
+        ['1', '2']
+        >>> len(view)
+        4
+
+    Sequence views are useful as an alternative to copying, as they don't
+    require (much) extra storage.
+
+    """
+
+    def __init__(self, target):
+        if not isinstance(target, Sequence):
+            raise TypeError
+        self._target = target
+
+    def __getitem__(self, index):
+        return self._target[index]
+
+    def __len__(self):
+        return len(self._target)
+
+    def __repr__(self):
+        return '{}({})'.format(self.__class__.__name__, repr(self._target))
+
+
+class seekable:
+    """Wrap an iterator to allow for seeking backward and forward. This
+    progressively caches the items in the source iterable so they can be
+    re-visited.
+
+    Call :meth:`seek` with an index to seek to that position in the source
+    iterable.
+
+    To "reset" an iterator, seek to ``0``:
+
+        >>> from itertools import count
+        >>> it = seekable((str(n) for n in count()))
+        >>> next(it), next(it), next(it)
+        ('0', '1', '2')
+        >>> it.seek(0)
+        >>> next(it), next(it), next(it)
+        ('0', '1', '2')
+        >>> next(it)
+        '3'
+
+    You can also seek forward:
+
+        >>> it = seekable((str(n) for n in range(20)))
+        >>> it.seek(10)
+        >>> next(it)
+        '10'
+        >>> it.seek(20)  # Seeking past the end of the source isn't a problem
+        >>> list(it)
+        []
+        >>> it.seek(0)  # Resetting works even after hitting the end
+        >>> next(it), next(it), next(it)
+        ('0', '1', '2')
+
+    Call :meth:`peek` to look ahead one item without advancing the iterator:
+
+        >>> it = seekable('1234')
+        >>> it.peek()
+        '1'
+        >>> list(it)
+        ['1', '2', '3', '4']
+        >>> it.peek(default='empty')
+        'empty'
+
+    Before the iterator is at its end, calling :func:`bool` on it will return
+    ``True``. After it will return ``False``:
+
+        >>> it = seekable('5678')
+        >>> bool(it)
+        True
+        >>> list(it)
+        ['5', '6', '7', '8']
+        >>> bool(it)
+        False
+
+    You may view the contents of the cache with the :meth:`elements` method.
+    That returns a :class:`SequenceView`, a view that updates automatically:
+
+        >>> it = seekable((str(n) for n in range(10)))
+        >>> next(it), next(it), next(it)
+        ('0', '1', '2')
+        >>> elements = it.elements()
+        >>> elements
+        SequenceView(['0', '1', '2'])
+        >>> next(it)
+        '3'
+        >>> elements
+        SequenceView(['0', '1', '2', '3'])
+
+    By default, the cache grows as the source iterable progresses, so beware of
+    wrapping very large or infinite iterables. Supply *maxlen* to limit the
+    size of the cache (this of course limits how far back you can seek).
+
+        >>> from itertools import count
+        >>> it = seekable((str(n) for n in count()), maxlen=2)
+        >>> next(it), next(it), next(it), next(it)
+        ('0', '1', '2', '3')
+        >>> list(it.elements())
+        ['2', '3']
+        >>> it.seek(0)
+        >>> next(it), next(it), next(it), next(it)
+        ('2', '3', '4', '5')
+        >>> next(it)
+        '6'
+
+    """
+
+    def __init__(self, iterable, maxlen=None):
+        self._source = iter(iterable)
+        if maxlen is None:
+            self._cache = []
+        else:
+            self._cache = deque([], maxlen)
+        self._index = None
+
+    def __iter__(self):
+        return self
+
+    def __next__(self):
+        if self._index is not None:
+            try:
+                item = self._cache[self._index]
+            except IndexError:
+                self._index = None
+            else:
+                self._index += 1
+                return item
+
+        item = next(self._source)
+        self._cache.append(item)
+        return item
+
+    def __bool__(self):
+        try:
+            self.peek()
+        except StopIteration:
+            return False
+        return True
+
+    def peek(self, default=_marker):
+        try:
+            peeked = next(self)
+        except StopIteration:
+            if default is _marker:
+                raise
+            return default
+        if self._index is None:
+            self._index = len(self._cache)
+        self._index -= 1
+        return peeked
+
+    def elements(self):
+        return SequenceView(self._cache)
+
+    def seek(self, index):
+        self._index = index
+        remainder = index - len(self._cache)
+        if remainder > 0:
+            consume(self, remainder)
+
+
+class run_length:
+    """
+    :func:`run_length.encode` compresses an iterable with run-length encoding.
+    It yields groups of repeated items with the count of how many times they
+    were repeated:
+
+        >>> uncompressed = 'abbcccdddd'
+        >>> list(run_length.encode(uncompressed))
+        [('a', 1), ('b', 2), ('c', 3), ('d', 4)]
+
+    :func:`run_length.decode` decompresses an iterable that was previously
+    compressed with run-length encoding. It yields the items of the
+    decompressed iterable:
+
+        >>> compressed = [('a', 1), ('b', 2), ('c', 3), ('d', 4)]
+        >>> list(run_length.decode(compressed))
+        ['a', 'b', 'b', 'c', 'c', 'c', 'd', 'd', 'd', 'd']
+
+    """
+
+    @staticmethod
+    def encode(iterable):
+        return ((k, ilen(g)) for k, g in groupby(iterable))
+
+    @staticmethod
+    def decode(iterable):
+        return chain.from_iterable(repeat(k, n) for k, n in iterable)
+
+
+def exactly_n(iterable, n, predicate=bool):
+    """Return ``True`` if exactly ``n`` items in the iterable are ``True``
+    according to the *predicate* function.
+
+        >>> exactly_n([True, True, False], 2)
+        True
+        >>> exactly_n([True, True, False], 1)
+        False
+        >>> exactly_n([0, 1, 2, 3, 4, 5], 3, lambda x: x < 3)
+        True
+
+    The iterable will be advanced until ``n + 1`` truthy items are encountered,
+    so avoid calling it on infinite iterables.
+
+    """
+    return len(take(n + 1, filter(predicate, iterable))) == n
+
+
+def circular_shifts(iterable):
+    """Return a list of circular shifts of *iterable*.
+
+    >>> circular_shifts(range(4))
+    [(0, 1, 2, 3), (1, 2, 3, 0), (2, 3, 0, 1), (3, 0, 1, 2)]
+    """
+    lst = list(iterable)
+    return take(len(lst), windowed(cycle(lst), len(lst)))
+
+
+def make_decorator(wrapping_func, result_index=0):
+    """Return a decorator version of *wrapping_func*, which is a function that
+    modifies an iterable. *result_index* is the position in that function's
+    signature where the iterable goes.
+
+    This lets you use itertools on the "production end," i.e. at function
+    definition. This can augment what the function returns without changing the
+    function's code.
+
+    For example, to produce a decorator version of :func:`chunked`:
+
+        >>> from more_itertools import chunked
+        >>> chunker = make_decorator(chunked, result_index=0)
+        >>> @chunker(3)
+        ... def iter_range(n):
+        ...     return iter(range(n))
+        ...
+        >>> list(iter_range(9))
+        [[0, 1, 2], [3, 4, 5], [6, 7, 8]]
+
+    To only allow truthy items to be returned:
+
+        >>> truth_serum = make_decorator(filter, result_index=1)
+        >>> @truth_serum(bool)
+        ... def boolean_test():
+        ...     return [0, 1, '', ' ', False, True]
+        ...
+        >>> list(boolean_test())
+        [1, ' ', True]
+
+    The :func:`peekable` and :func:`seekable` wrappers make for practical
+    decorators:
+
+        >>> from more_itertools import peekable
+        >>> peekable_function = make_decorator(peekable)
+        >>> @peekable_function()
+        ... def str_range(*args):
+        ...     return (str(x) for x in range(*args))
+        ...
+        >>> it = str_range(1, 20, 2)
+        >>> next(it), next(it), next(it)
+        ('1', '3', '5')
+        >>> it.peek()
+        '7'
+        >>> next(it)
+        '7'
+
+    """
+
+    # See https://sites.google.com/site/bbayles/index/decorator_factory for
+    # notes on how this works.
+    def decorator(*wrapping_args, **wrapping_kwargs):
+        def outer_wrapper(f):
+            def inner_wrapper(*args, **kwargs):
+                result = f(*args, **kwargs)
+                wrapping_args_ = list(wrapping_args)
+                wrapping_args_.insert(result_index, result)
+                return wrapping_func(*wrapping_args_, **wrapping_kwargs)
+
+            return inner_wrapper
+
+        return outer_wrapper
+
+    return decorator
+
+
+def map_reduce(iterable, keyfunc, valuefunc=None, reducefunc=None):
+    """Return a dictionary that maps the items in *iterable* to categories
+    defined by *keyfunc*, transforms them with *valuefunc*, and
+    then summarizes them by category with *reducefunc*.
+
+    *valuefunc* defaults to the identity function if it is unspecified.
+    If *reducefunc* is unspecified, no summarization takes place:
+
+        >>> keyfunc = lambda x: x.upper()
+        >>> result = map_reduce('abbccc', keyfunc)
+        >>> sorted(result.items())
+        [('A', ['a']), ('B', ['b', 'b']), ('C', ['c', 'c', 'c'])]
+
+    Specifying *valuefunc* transforms the categorized items:
+
+        >>> keyfunc = lambda x: x.upper()
+        >>> valuefunc = lambda x: 1
+        >>> result = map_reduce('abbccc', keyfunc, valuefunc)
+        >>> sorted(result.items())
+        [('A', [1]), ('B', [1, 1]), ('C', [1, 1, 1])]
+
+    Specifying *reducefunc* summarizes the categorized items:
+
+        >>> keyfunc = lambda x: x.upper()
+        >>> valuefunc = lambda x: 1
+        >>> reducefunc = sum
+        >>> result = map_reduce('abbccc', keyfunc, valuefunc, reducefunc)
+        >>> sorted(result.items())
+        [('A', 1), ('B', 2), ('C', 3)]
+
+    You may want to filter the input iterable before applying the map/reduce
+    procedure:
+
+        >>> all_items = range(30)
+        >>> items = [x for x in all_items if 10 <= x <= 20]  # Filter
+        >>> keyfunc = lambda x: x % 2  # Evens map to 0; odds to 1
+        >>> categories = map_reduce(items, keyfunc=keyfunc)
+        >>> sorted(categories.items())
+        [(0, [10, 12, 14, 16, 18, 20]), (1, [11, 13, 15, 17, 19])]
+        >>> summaries = map_reduce(items, keyfunc=keyfunc, reducefunc=sum)
+        >>> sorted(summaries.items())
+        [(0, 90), (1, 75)]
+
+    Note that all items in the iterable are gathered into a list before the
+    summarization step, which may require significant storage.
+
+    The returned object is a :obj:`collections.defaultdict` with the
+    ``default_factory`` set to ``None``, such that it behaves like a normal
+    dictionary.
+
+    """
+    valuefunc = (lambda x: x) if (valuefunc is None) else valuefunc
+
+    ret = defaultdict(list)
+    for item in iterable:
+        key = keyfunc(item)
+        value = valuefunc(item)
+        ret[key].append(value)
+
+    if reducefunc is not None:
+        for key, value_list in ret.items():
+            ret[key] = reducefunc(value_list)
+
+    ret.default_factory = None
+    return ret
+
+
+def rlocate(iterable, pred=bool, window_size=None):
+    """Yield the index of each item in *iterable* for which *pred* returns
+    ``True``, starting from the right and moving left.
+
+    *pred* defaults to :func:`bool`, which will select truthy items:
+
+        >>> list(rlocate([0, 1, 1, 0, 1, 0, 0]))  # Truthy at 1, 2, and 4
+        [4, 2, 1]
+
+    Set *pred* to a custom function to, e.g., find the indexes for a particular
+    item:
+
+        >>> iterable = iter('abcb')
+        >>> pred = lambda x: x == 'b'
+        >>> list(rlocate(iterable, pred))
+        [3, 1]
+
+    If *window_size* is given, then the *pred* function will be called with
+    that many items. This enables searching for sub-sequences:
+
+        >>> iterable = [0, 1, 2, 3, 0, 1, 2, 3, 0, 1, 2, 3]
+        >>> pred = lambda *args: args == (1, 2, 3)
+        >>> list(rlocate(iterable, pred=pred, window_size=3))
+        [9, 5, 1]
+
+    Beware, this function won't return anything for infinite iterables.
+    If *iterable* is reversible, ``rlocate`` will reverse it and search from
+    the right. Otherwise, it will search from the left and return the results
+    in reverse order.
+
+    See :func:`locate` to for other example applications.
+
+    """
+    if window_size is None:
+        try:
+            len_iter = len(iterable)
+            return (len_iter - i - 1 for i in locate(reversed(iterable), pred))
+        except TypeError:
+            pass
+
+    return reversed(list(locate(iterable, pred, window_size)))
+
+
+def replace(iterable, pred, substitutes, count=None, window_size=1):
+    """Yield the items from *iterable*, replacing the items for which *pred*
+    returns ``True`` with the items from the iterable *substitutes*.
+
+        >>> iterable = [1, 1, 0, 1, 1, 0, 1, 1]
+        >>> pred = lambda x: x == 0
+        >>> substitutes = (2, 3)
+        >>> list(replace(iterable, pred, substitutes))
+        [1, 1, 2, 3, 1, 1, 2, 3, 1, 1]
+
+    If *count* is given, the number of replacements will be limited:
+
+        >>> iterable = [1, 1, 0, 1, 1, 0, 1, 1, 0]
+        >>> pred = lambda x: x == 0
+        >>> substitutes = [None]
+        >>> list(replace(iterable, pred, substitutes, count=2))
+        [1, 1, None, 1, 1, None, 1, 1, 0]
+
+    Use *window_size* to control the number of items passed as arguments to
+    *pred*. This allows for locating and replacing subsequences.
+
+        >>> iterable = [0, 1, 2, 5, 0, 1, 2, 5]
+        >>> window_size = 3
+        >>> pred = lambda *args: args == (0, 1, 2)  # 3 items passed to pred
+        >>> substitutes = [3, 4] # Splice in these items
+        >>> list(replace(iterable, pred, substitutes, window_size=window_size))
+        [3, 4, 5, 3, 4, 5]
+
+    """
+    if window_size < 1:
+        raise ValueError('window_size must be at least 1')
+
+    # Save the substitutes iterable, since it's used more than once
+    substitutes = tuple(substitutes)
+
+    # Add padding such that the number of windows matches the length of the
+    # iterable
+    it = chain(iterable, [_marker] * (window_size - 1))
+    windows = windowed(it, window_size)
+
+    n = 0
+    for w in windows:
+        # If the current window matches our predicate (and we haven't hit
+        # our maximum number of replacements), splice in the substitutes
+        # and then consume the following windows that overlap with this one.
+        # For example, if the iterable is (0, 1, 2, 3, 4...)
+        # and the window size is 2, we have (0, 1), (1, 2), (2, 3)...
+        # If the predicate matches on (0, 1), we need to zap (0, 1) and (1, 2)
+        if pred(*w):
+            if (count is None) or (n < count):
+                n += 1
+                yield from substitutes
+                consume(windows, window_size - 1)
+                continue
+
+        # If there was no match (or we've reached the replacement limit),
+        # yield the first item from the window.
+        if w and (w[0] is not _marker):
+            yield w[0]
+
+
+def partitions(iterable):
+    """Yield all possible order-preserving partitions of *iterable*.
+
+    >>> iterable = 'abc'
+    >>> for part in partitions(iterable):
+    ...     print([''.join(p) for p in part])
+    ['abc']
+    ['a', 'bc']
+    ['ab', 'c']
+    ['a', 'b', 'c']
+
+    This is unrelated to :func:`partition`.
+
+    """
+    sequence = list(iterable)
+    n = len(sequence)
+    for i in powerset(range(1, n)):
+        yield [sequence[i:j] for i, j in zip((0,) + i, i + (n,))]
+
+
+def set_partitions(iterable, k=None):
+    """
+    Yield the set partitions of *iterable* into *k* parts. Set partitions are
+    not order-preserving.
+
+    >>> iterable = 'abc'
+    >>> for part in set_partitions(iterable, 2):
+    ...     print([''.join(p) for p in part])
+    ['a', 'bc']
+    ['ab', 'c']
+    ['b', 'ac']
+
+
+    If *k* is not given, every set partition is generated.
+
+    >>> iterable = 'abc'
+    >>> for part in set_partitions(iterable):
+    ...     print([''.join(p) for p in part])
+    ['abc']
+    ['a', 'bc']
+    ['ab', 'c']
+    ['b', 'ac']
+    ['a', 'b', 'c']
+
+    """
+    L = list(iterable)
+    n = len(L)
+    if k is not None:
+        if k < 1:
+            raise ValueError(
+                "Can't partition in a negative or zero number of groups"
+            )
+        elif k > n:
+            return
+
+    def set_partitions_helper(L, k):
+        n = len(L)
+        if k == 1:
+            yield [L]
+        elif n == k:
+            yield [[s] for s in L]
+        else:
+            e, *M = L
+            for p in set_partitions_helper(M, k - 1):
+                yield [[e], *p]
+            for p in set_partitions_helper(M, k):
+                for i in range(len(p)):
+                    yield p[:i] + [[e] + p[i]] + p[i + 1 :]
+
+    if k is None:
+        for k in range(1, n + 1):
+            yield from set_partitions_helper(L, k)
+    else:
+        yield from set_partitions_helper(L, k)
+
+
+class time_limited:
+    """
+    Yield items from *iterable* until *limit_seconds* have passed.
+    If the time limit expires before all items have been yielded, the
+    ``timed_out`` parameter will be set to ``True``.
+
+    >>> from time import sleep
+    >>> def generator():
+    ...     yield 1
+    ...     yield 2
+    ...     sleep(0.2)
+    ...     yield 3
+    >>> iterable = time_limited(0.1, generator())
+    >>> list(iterable)
+    [1, 2]
+    >>> iterable.timed_out
+    True
+
+    Note that the time is checked before each item is yielded, and iteration
+    stops if  the time elapsed is greater than *limit_seconds*. If your time
+    limit is 1 second, but it takes 2 seconds to generate the first item from
+    the iterable, the function will run for 2 seconds and not yield anything.
+
+    """
+
+    def __init__(self, limit_seconds, iterable):
+        if limit_seconds < 0:
+            raise ValueError('limit_seconds must be positive')
+        self.limit_seconds = limit_seconds
+        self._iterable = iter(iterable)
+        self._start_time = monotonic()
+        self.timed_out = False
+
+    def __iter__(self):
+        return self
+
+    def __next__(self):
+        item = next(self._iterable)
+        if monotonic() - self._start_time > self.limit_seconds:
+            self.timed_out = True
+            raise StopIteration
+
+        return item
+
+
+def only(iterable, default=None, too_long=None):
+    """If *iterable* has only one item, return it.
+    If it has zero items, return *default*.
+    If it has more than one item, raise the exception given by *too_long*,
+    which is ``ValueError`` by default.
+
+    >>> only([], default='missing')
+    'missing'
+    >>> only([1])
+    1
+    >>> only([1, 2])  # doctest: +IGNORE_EXCEPTION_DETAIL
+    Traceback (most recent call last):
+    ...
+    ValueError: Expected exactly one item in iterable, but got 1, 2,
+     and perhaps more.'
+    >>> only([1, 2], too_long=TypeError)  # doctest: +IGNORE_EXCEPTION_DETAIL
+    Traceback (most recent call last):
+    ...
+    TypeError
+
+    Note that :func:`only` attempts to advance *iterable* twice to ensure there
+    is only one item.  See :func:`spy` or :func:`peekable` to check
+    iterable contents less destructively.
+    """
+    it = iter(iterable)
+    first_value = next(it, default)
+
+    try:
+        second_value = next(it)
+    except StopIteration:
+        pass
+    else:
+        msg = (
+            'Expected exactly one item in iterable, but got {!r}, {!r}, '
+            'and perhaps more.'.format(first_value, second_value)
+        )
+        raise too_long or ValueError(msg)
+
+    return first_value
+
+
+class _IChunk:
+    def __init__(self, iterable, n):
+        self._it = islice(iterable, n)
+        self._cache = deque()
+
+    def fill_cache(self):
+        self._cache.extend(self._it)
+
+    def __iter__(self):
+        return self
+
+    def __next__(self):
+        try:
+            return next(self._it)
+        except StopIteration:
+            if self._cache:
+                return self._cache.popleft()
+            else:
+                raise
+
+
+def ichunked(iterable, n):
+    """Break *iterable* into sub-iterables with *n* elements each.
+    :func:`ichunked` is like :func:`chunked`, but it yields iterables
+    instead of lists.
+
+    If the sub-iterables are read in order, the elements of *iterable*
+    won't be stored in memory.
+    If they are read out of order, :func:`itertools.tee` is used to cache
+    elements as necessary.
+
+    >>> from itertools import count
+    >>> all_chunks = ichunked(count(), 4)
+    >>> c_1, c_2, c_3 = next(all_chunks), next(all_chunks), next(all_chunks)
+    >>> list(c_2)  # c_1's elements have been cached; c_3's haven't been
+    [4, 5, 6, 7]
+    >>> list(c_1)
+    [0, 1, 2, 3]
+    >>> list(c_3)
+    [8, 9, 10, 11]
+
+    """
+    source = peekable(iter(iterable))
+    ichunk_marker = object()
+    while True:
+        # Check to see whether we're at the end of the source iterable
+        item = source.peek(ichunk_marker)
+        if item is ichunk_marker:
+            return
+
+        chunk = _IChunk(source, n)
+        yield chunk
+
+        # Advance the source iterable and fill previous chunk's cache
+        chunk.fill_cache()
+
+
+def iequals(*iterables):
+    """Return ``True`` if all given *iterables* are equal to each other,
+    which means that they contain the same elements in the same order.
+
+    The function is useful for comparing iterables of different data types
+    or iterables that do not support equality checks.
+
+    >>> iequals("abc", ['a', 'b', 'c'], ('a', 'b', 'c'), iter("abc"))
+    True
+
+    >>> iequals("abc", "acb")
+    False
+
+    Not to be confused with :func:`all_equals`, which checks whether all
+    elements of iterable are equal to each other.
+
+    """
+    return all(map(all_equal, zip_longest(*iterables, fillvalue=object())))
+
+
+def distinct_combinations(iterable, r):
+    """Yield the distinct combinations of *r* items taken from *iterable*.
+
+        >>> list(distinct_combinations([0, 0, 1], 2))
+        [(0, 0), (0, 1)]
+
+    Equivalent to ``set(combinations(iterable))``, except duplicates are not
+    generated and thrown away. For larger input sequences this is much more
+    efficient.
+
+    """
+    if r < 0:
+        raise ValueError('r must be non-negative')
+    elif r == 0:
+        yield ()
+        return
+    pool = tuple(iterable)
+    generators = [unique_everseen(enumerate(pool), key=itemgetter(1))]
+    current_combo = [None] * r
+    level = 0
+    while generators:
+        try:
+            cur_idx, p = next(generators[-1])
+        except StopIteration:
+            generators.pop()
+            level -= 1
+            continue
+        current_combo[level] = p
+        if level + 1 == r:
+            yield tuple(current_combo)
+        else:
+            generators.append(
+                unique_everseen(
+                    enumerate(pool[cur_idx + 1 :], cur_idx + 1),
+                    key=itemgetter(1),
+                )
+            )
+            level += 1
+
+
+def filter_except(validator, iterable, *exceptions):
+    """Yield the items from *iterable* for which the *validator* function does
+    not raise one of the specified *exceptions*.
+
+    *validator* is called for each item in *iterable*.
+    It should be a function that accepts one argument and raises an exception
+    if that item is not valid.
+
+    >>> iterable = ['1', '2', 'three', '4', None]
+    >>> list(filter_except(int, iterable, ValueError, TypeError))
+    ['1', '2', '4']
+
+    If an exception other than one given by *exceptions* is raised by
+    *validator*, it is raised like normal.
+    """
+    for item in iterable:
+        try:
+            validator(item)
+        except exceptions:
+            pass
+        else:
+            yield item
+
+
+def map_except(function, iterable, *exceptions):
+    """Transform each item from *iterable* with *function* and yield the
+    result, unless *function* raises one of the specified *exceptions*.
+
+    *function* is called to transform each item in *iterable*.
+    It should accept one argument.
+
+    >>> iterable = ['1', '2', 'three', '4', None]
+    >>> list(map_except(int, iterable, ValueError, TypeError))
+    [1, 2, 4]
+
+    If an exception other than one given by *exceptions* is raised by
+    *function*, it is raised like normal.
+    """
+    for item in iterable:
+        try:
+            yield function(item)
+        except exceptions:
+            pass
+
+
+def map_if(iterable, pred, func, func_else=lambda x: x):
+    """Evaluate each item from *iterable* using *pred*. If the result is
+    equivalent to ``True``, transform the item with *func* and yield it.
+    Otherwise, transform the item with *func_else* and yield it.
+
+    *pred*, *func*, and *func_else* should each be functions that accept
+    one argument. By default, *func_else* is the identity function.
+
+    >>> from math import sqrt
+    >>> iterable = list(range(-5, 5))
+    >>> iterable
+    [-5, -4, -3, -2, -1, 0, 1, 2, 3, 4]
+    >>> list(map_if(iterable, lambda x: x > 3, lambda x: 'toobig'))
+    [-5, -4, -3, -2, -1, 0, 1, 2, 3, 'toobig']
+    >>> list(map_if(iterable, lambda x: x >= 0,
+    ... lambda x: f'{sqrt(x):.2f}', lambda x: None))
+    [None, None, None, None, None, '0.00', '1.00', '1.41', '1.73', '2.00']
+    """
+    for item in iterable:
+        yield func(item) if pred(item) else func_else(item)
+
+
+def _sample_unweighted(iterable, k):
+    # Implementation of "Algorithm L" from the 1994 paper by Kim-Hung Li:
+    # "Reservoir-Sampling Algorithms of Time Complexity O(n(1+log(N/n)))".
+
+    # Fill up the reservoir (collection of samples) with the first `k` samples
+    reservoir = take(k, iterable)
+
+    # Generate random number that's the largest in a sample of k U(0,1) numbers
+    # Largest order statistic: https://en.wikipedia.org/wiki/Order_statistic
+    W = exp(log(random()) / k)
+
+    # The number of elements to skip before changing the reservoir is a random
+    # number with a geometric distribution. Sample it using random() and logs.
+    next_index = k + floor(log(random()) / log(1 - W))
+
+    for index, element in enumerate(iterable, k):
+        if index == next_index:
+            reservoir[randrange(k)] = element
+            # The new W is the largest in a sample of k U(0, `old_W`) numbers
+            W *= exp(log(random()) / k)
+            next_index += floor(log(random()) / log(1 - W)) + 1
+
+    return reservoir
+
+
+def _sample_weighted(iterable, k, weights):
+    # Implementation of "A-ExpJ" from the 2006 paper by Efraimidis et al. :
+    # "Weighted random sampling with a reservoir".
+
+    # Log-transform for numerical stability for weights that are small/large
+    weight_keys = (log(random()) / weight for weight in weights)
+
+    # Fill up the reservoir (collection of samples) with the first `k`
+    # weight-keys and elements, then heapify the list.
+    reservoir = take(k, zip(weight_keys, iterable))
+    heapify(reservoir)
+
+    # The number of jumps before changing the reservoir is a random variable
+    # with an exponential distribution. Sample it using random() and logs.
+    smallest_weight_key, _ = reservoir[0]
+    weights_to_skip = log(random()) / smallest_weight_key
+
+    for weight, element in zip(weights, iterable):
+        if weight >= weights_to_skip:
+            # The notation here is consistent with the paper, but we store
+            # the weight-keys in log-space for better numerical stability.
+            smallest_weight_key, _ = reservoir[0]
+            t_w = exp(weight * smallest_weight_key)
+            r_2 = uniform(t_w, 1)  # generate U(t_w, 1)
+            weight_key = log(r_2) / weight
+            heapreplace(reservoir, (weight_key, element))
+            smallest_weight_key, _ = reservoir[0]
+            weights_to_skip = log(random()) / smallest_weight_key
+        else:
+            weights_to_skip -= weight
+
+    # Equivalent to [element for weight_key, element in sorted(reservoir)]
+    return [heappop(reservoir)[1] for _ in range(k)]
+
+
+def sample(iterable, k, weights=None):
+    """Return a *k*-length list of elements chosen (without replacement)
+    from the *iterable*. Like :func:`random.sample`, but works on iterables
+    of unknown length.
+
+    >>> iterable = range(100)
+    >>> sample(iterable, 5)  # doctest: +SKIP
+    [81, 60, 96, 16, 4]
+
+    An iterable with *weights* may also be given:
+
+    >>> iterable = range(100)
+    >>> weights = (i * i + 1 for i in range(100))
+    >>> sampled = sample(iterable, 5, weights=weights)  # doctest: +SKIP
+    [79, 67, 74, 66, 78]
+
+    The algorithm can also be used to generate weighted random permutations.
+    The relative weight of each item determines the probability that it
+    appears late in the permutation.
+
+    >>> data = "abcdefgh"
+    >>> weights = range(1, len(data) + 1)
+    >>> sample(data, k=len(data), weights=weights)  # doctest: +SKIP
+    ['c', 'a', 'b', 'e', 'g', 'd', 'h', 'f']
+    """
+    if k == 0:
+        return []
+
+    iterable = iter(iterable)
+    if weights is None:
+        return _sample_unweighted(iterable, k)
+    else:
+        weights = iter(weights)
+        return _sample_weighted(iterable, k, weights)
+
+
+def is_sorted(iterable, key=None, reverse=False, strict=False):
+    """Returns ``True`` if the items of iterable are in sorted order, and
+    ``False`` otherwise. *key* and *reverse* have the same meaning that they do
+    in the built-in :func:`sorted` function.
+
+    >>> is_sorted(['1', '2', '3', '4', '5'], key=int)
+    True
+    >>> is_sorted([5, 4, 3, 1, 2], reverse=True)
+    False
+
+    If *strict*, tests for strict sorting, that is, returns ``False`` if equal
+    elements are found:
+
+    >>> is_sorted([1, 2, 2])
+    True
+    >>> is_sorted([1, 2, 2], strict=True)
+    False
+
+    The function returns ``False`` after encountering the first out-of-order
+    item. If there are no out-of-order items, the iterable is exhausted.
+    """
+
+    compare = (le if reverse else ge) if strict else (lt if reverse else gt)
+    it = iterable if key is None else map(key, iterable)
+    return not any(starmap(compare, pairwise(it)))
+
+
+class AbortThread(BaseException):
+    pass
+
+
+class callback_iter:
+    """Convert a function that uses callbacks to an iterator.
+
+    Let *func* be a function that takes a `callback` keyword argument.
+    For example:
+
+    >>> def func(callback=None):
+    ...     for i, c in [(1, 'a'), (2, 'b'), (3, 'c')]:
+    ...         if callback:
+    ...             callback(i, c)
+    ...     return 4
+
+
+    Use ``with callback_iter(func)`` to get an iterator over the parameters
+    that are delivered to the callback.
+
+    >>> with callback_iter(func) as it:
+    ...     for args, kwargs in it:
+    ...         print(args)
+    (1, 'a')
+    (2, 'b')
+    (3, 'c')
+
+    The function will be called in a background thread. The ``done`` property
+    indicates whether it has completed execution.
+
+    >>> it.done
+    True
+
+    If it completes successfully, its return value will be available
+    in the ``result`` property.
+
+    >>> it.result
+    4
+
+    Notes:
+
+    * If the function uses some keyword argument besides ``callback``, supply
+      *callback_kwd*.
+    * If it finished executing, but raised an exception, accessing the
+      ``result`` property will raise the same exception.
+    * If it hasn't finished executing, accessing the ``result``
+      property from within the ``with`` block will raise ``RuntimeError``.
+    * If it hasn't finished executing, accessing the ``result`` property from
+      outside the ``with`` block will raise a
+      ``more_itertools.AbortThread`` exception.
+    * Provide *wait_seconds* to adjust how frequently the it is polled for
+      output.
+
+    """
+
+    def __init__(self, func, callback_kwd='callback', wait_seconds=0.1):
+        self._func = func
+        self._callback_kwd = callback_kwd
+        self._aborted = False
+        self._future = None
+        self._wait_seconds = wait_seconds
+        # Lazily import concurrent.future
+        self._executor = __import__(
+        ).futures.__import__("concurrent.futures").futures.ThreadPoolExecutor(max_workers=1)
+        self._iterator = self._reader()
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, exc_type, exc_value, traceback):
+        self._aborted = True
+        self._executor.shutdown()
+
+    def __iter__(self):
+        return self
+
+    def __next__(self):
+        return next(self._iterator)
+
+    @property
+    def done(self):
+        if self._future is None:
+            return False
+        return self._future.done()
+
+    @property
+    def result(self):
+        if not self.done:
+            raise RuntimeError('Function has not yet completed')
+
+        return self._future.result()
+
+    def _reader(self):
+        q = Queue()
+
+        def callback(*args, **kwargs):
+            if self._aborted:
+                raise AbortThread('canceled by user')
+
+            q.put((args, kwargs))
+
+        self._future = self._executor.submit(
+            self._func, **{self._callback_kwd: callback}
+        )
+
+        while True:
+            try:
+                item = q.get(timeout=self._wait_seconds)
+            except Empty:
+                pass
+            else:
+                q.task_done()
+                yield item
+
+            if self._future.done():
+                break
+
+        remaining = []
+        while True:
+            try:
+                item = q.get_nowait()
+            except Empty:
+                break
+            else:
+                q.task_done()
+                remaining.append(item)
+        q.join()
+        yield from remaining
+
+
+def windowed_complete(iterable, n):
+    """
+    Yield ``(beginning, middle, end)`` tuples, where:
+
+    * Each ``middle`` has *n* items from *iterable*
+    * Each ``beginning`` has the items before the ones in ``middle``
+    * Each ``end`` has the items after the ones in ``middle``
+
+    >>> iterable = range(7)
+    >>> n = 3
+    >>> for beginning, middle, end in windowed_complete(iterable, n):
+    ...     print(beginning, middle, end)
+    () (0, 1, 2) (3, 4, 5, 6)
+    (0,) (1, 2, 3) (4, 5, 6)
+    (0, 1) (2, 3, 4) (5, 6)
+    (0, 1, 2) (3, 4, 5) (6,)
+    (0, 1, 2, 3) (4, 5, 6) ()
+
+    Note that *n* must be at least 0 and most equal to the length of
+    *iterable*.
+
+    This function will exhaust the iterable and may require significant
+    storage.
+    """
+    if n < 0:
+        raise ValueError('n must be >= 0')
+
+    seq = tuple(iterable)
+    size = len(seq)
+
+    if n > size:
+        raise ValueError('n must be <= len(seq)')
+
+    for i in range(size - n + 1):
+        beginning = seq[:i]
+        middle = seq[i : i + n]
+        end = seq[i + n :]
+        yield beginning, middle, end
+
+
+def all_unique(iterable, key=None):
+    """
+    Returns ``True`` if all the elements of *iterable* are unique (no two
+    elements are equal).
+
+        >>> all_unique('ABCB')
+        False
+
+    If a *key* function is specified, it will be used to make comparisons.
+
+        >>> all_unique('ABCb')
+        True
+        >>> all_unique('ABCb', str.lower)
+        False
+
+    The function returns as soon as the first non-unique element is
+    encountered. Iterables with a mix of hashable and unhashable items can
+    be used, but the function will be slower for unhashable items.
+    """
+    seenset = set()
+    seenset_add = seenset.add
+    seenlist = []
+    seenlist_add = seenlist.append
+    for element in map(key, iterable) if key else iterable:
+        try:
+            if element in seenset:
+                return False
+            seenset_add(element)
+        except TypeError:
+            if element in seenlist:
+                return False
+            seenlist_add(element)
+    return True
+
+
+def nth_product(index, *args):
+    """Equivalent to ``list(product(*args))[index]``.
+
+    The products of *args* can be ordered lexicographically.
+    :func:`nth_product` computes the product at sort position *index* without
+    computing the previous products.
+
+        >>> nth_product(8, range(2), range(2), range(2), range(2))
+        (1, 0, 0, 0)
+
+    ``IndexError`` will be raised if the given *index* is invalid.
+    """
+    pools = list(map(tuple, reversed(args)))
+    ns = list(map(len, pools))
+
+    c = reduce(mul, ns)
+
+    if index < 0:
+        index += c
+
+    if not 0 <= index < c:
+        raise IndexError
+
+    result = []
+    for pool, n in zip(pools, ns):
+        result.append(pool[index % n])
+        index //= n
+
+    return tuple(reversed(result))
+
+
+def nth_permutation(iterable, r, index):
+    """Equivalent to ``list(permutations(iterable, r))[index]```
+
+    The subsequences of *iterable* that are of length *r* where order is
+    important can be ordered lexicographically. :func:`nth_permutation`
+    computes the subsequence at sort position *index* directly, without
+    computing the previous subsequences.
+
+        >>> nth_permutation('ghijk', 2, 5)
+        ('h', 'i')
+
+    ``ValueError`` will be raised If *r* is negative or greater than the length
+    of *iterable*.
+    ``IndexError`` will be raised if the given *index* is invalid.
+    """
+    pool = list(iterable)
+    n = len(pool)
+
+    if r is None or r == n:
+        r, c = n, factorial(n)
+    elif not 0 <= r < n:
+        raise ValueError
+    else:
+        c = factorial(n) // factorial(n - r)
+
+    if index < 0:
+        index += c
+
+    if not 0 <= index < c:
+        raise IndexError
+
+    if c == 0:
+        return tuple()
+
+    result = [0] * r
+    q = index * factorial(n) // c if r < n else index
+    for d in range(1, n + 1):
+        q, i = divmod(q, d)
+        if 0 <= n - d < r:
+            result[n - d] = i
+        if q == 0:
+            break
+
+    return tuple(map(pool.pop, result))
+
+
+def value_chain(*args):
+    """Yield all arguments passed to the function in the same order in which
+    they were passed. If an argument itself is iterable then iterate over its
+    values.
+
+        >>> list(value_chain(1, 2, 3, [4, 5, 6]))
+        [1, 2, 3, 4, 5, 6]
+
+    Binary and text strings are not considered iterable and are emitted
+    as-is:
+
+        >>> list(value_chain('12', '34', ['56', '78']))
+        ['12', '34', '56', '78']
+
+
+    Multiple levels of nesting are not flattened.
+
+    """
+    for value in args:
+        if isinstance(value, (str, bytes)):
+            yield value
+            continue
+        try:
+            yield from value
+        except TypeError:
+            yield value
+
+
+def product_index(element, *args):
+    """Equivalent to ``list(product(*args)).index(element)``
+
+    The products of *args* can be ordered lexicographically.
+    :func:`product_index` computes the first index of *element* without
+    computing the previous products.
+
+        >>> product_index([8, 2], range(10), range(5))
+        42
+
+    ``ValueError`` will be raised if the given *element* isn't in the product
+    of *args*.
+    """
+    index = 0
+
+    for x, pool in zip_longest(element, args, fillvalue=_marker):
+        if x is _marker or pool is _marker:
+            raise ValueError('element is not a product of args')
+
+        pool = tuple(pool)
+        index = index * len(pool) + pool.index(x)
+
+    return index
+
+
+def combination_index(element, iterable):
+    """Equivalent to ``list(combinations(iterable, r)).index(element)``
+
+    The subsequences of *iterable* that are of length *r* can be ordered
+    lexicographically. :func:`combination_index` computes the index of the
+    first *element*, without computing the previous combinations.
+
+        >>> combination_index('adf', 'abcdefg')
+        10
+
+    ``ValueError`` will be raised if the given *element* isn't one of the
+    combinations of *iterable*.
+    """
+    element = enumerate(element)
+    k, y = next(element, (None, None))
+    if k is None:
+        return 0
+
+    indexes = []
+    pool = enumerate(iterable)
+    for n, x in pool:
+        if x == y:
+            indexes.append(n)
+            tmp, y = next(element, (None, None))
+            if tmp is None:
+                break
+            else:
+                k = tmp
+    else:
+        raise ValueError('element is not a combination of iterable')
+
+    n, _ = last(pool, default=(n, None))
+
+    # Python versions below 3.8 don't have math.comb
+    index = 1
+    for i, j in enumerate(reversed(indexes), start=1):
+        j = n - j
+        if i <= j:
+            index += factorial(j) // (factorial(i) * factorial(j - i))
+
+    return factorial(n + 1) // (factorial(k + 1) * factorial(n - k)) - index
+
+
+def permutation_index(element, iterable):
+    """Equivalent to ``list(permutations(iterable, r)).index(element)```
+
+    The subsequences of *iterable* that are of length *r* where order is
+    important can be ordered lexicographically. :func:`permutation_index`
+    computes the index of the first *element* directly, without computing
+    the previous permutations.
+
+        >>> permutation_index([1, 3, 2], range(5))
+        19
+
+    ``ValueError`` will be raised if the given *element* isn't one of the
+    permutations of *iterable*.
+    """
+    index = 0
+    pool = list(iterable)
+    for i, x in zip(range(len(pool), -1, -1), element):
+        r = pool.index(x)
+        index = index * i + r
+        del pool[r]
+
+    return index
+
+
+class countable:
+    """Wrap *iterable* and keep a count of how many items have been consumed.
+
+    The ``items_seen`` attribute starts at ``0`` and increments as the iterable
+    is consumed:
+
+        >>> iterable = map(str, range(10))
+        >>> it = countable(iterable)
+        >>> it.items_seen
+        0
+        >>> next(it), next(it)
+        ('0', '1')
+        >>> list(it)
+        ['2', '3', '4', '5', '6', '7', '8', '9']
+        >>> it.items_seen
+        10
+    """
+
+    def __init__(self, iterable):
+        self._it = iter(iterable)
+        self.items_seen = 0
+
+    def __iter__(self):
+        return self
+
+    def __next__(self):
+        item = next(self._it)
+        self.items_seen += 1
+
+        return item
+
+
+def chunked_even(iterable, n):
+    """Break *iterable* into lists of approximately length *n*.
+    Items are distributed such the lengths of the lists differ by at most
+    1 item.
+
+    >>> iterable = [1, 2, 3, 4, 5, 6, 7]
+    >>> n = 3
+    >>> list(chunked_even(iterable, n))  # List lengths: 3, 2, 2
+    [[1, 2, 3], [4, 5], [6, 7]]
+    >>> list(chunked(iterable, n))  # List lengths: 3, 3, 1
+    [[1, 2, 3], [4, 5, 6], [7]]
+
+    """
+
+    len_method = getattr(iterable, '__len__', None)
+
+    if len_method is None:
+        return _chunked_even_online(iterable, n)
+    else:
+        return _chunked_even_finite(iterable, len_method(), n)
+
+
+def _chunked_even_online(iterable, n):
+    buffer = []
+    maxbuf = n + (n - 2) * (n - 1)
+    for x in iterable:
+        buffer.append(x)
+        if len(buffer) == maxbuf:
+            yield buffer[:n]
+            buffer = buffer[n:]
+    yield from _chunked_even_finite(buffer, len(buffer), n)
+
+
+def _chunked_even_finite(iterable, N, n):
+    if N < 1:
+        return
+
+    # Lists are either size `full_size <= n` or `partial_size = full_size - 1`
+    q, r = divmod(N, n)
+    num_lists = q + (1 if r > 0 else 0)
+    q, r = divmod(N, num_lists)
+    full_size = q + (1 if r > 0 else 0)
+    partial_size = full_size - 1
+    num_full = N - partial_size * num_lists
+    num_partial = num_lists - num_full
+
+    buffer = []
+    iterator = iter(iterable)
+
+    # Yield num_full lists of full_size
+    for x in iterator:
+        buffer.append(x)
+        if len(buffer) == full_size:
+            yield buffer
+            buffer = []
+            num_full -= 1
+            if num_full <= 0:
+                break
+
+    # Yield num_partial lists of partial_size
+    for x in iterator:
+        buffer.append(x)
+        if len(buffer) == partial_size:
+            yield buffer
+            buffer = []
+            num_partial -= 1
+
+
+def zip_broadcast(*objects, scalar_types=(str, bytes), strict=False):
+    """A version of :func:`zip` that "broadcasts" any scalar
+    (i.e., non-iterable) items into output tuples.
+
+    >>> iterable_1 = [1, 2, 3]
+    >>> iterable_2 = ['a', 'b', 'c']
+    >>> scalar = '_'
+    >>> list(zip_broadcast(iterable_1, iterable_2, scalar))
+    [(1, 'a', '_'), (2, 'b', '_'), (3, 'c', '_')]
+
+    The *scalar_types* keyword argument determines what types are considered
+    scalar. It is set to ``(str, bytes)`` by default. Set it to ``None`` to
+    treat strings and byte strings as iterable:
+
+    >>> list(zip_broadcast('abc', 0, 'xyz', scalar_types=None))
+    [('a', 0, 'x'), ('b', 0, 'y'), ('c', 0, 'z')]
+
+    If the *strict* keyword argument is ``True``, then
+    ``UnequalIterablesError`` will be raised if any of the iterables have
+    different lengths.
+    """
+
+    def is_scalar(obj):
+        if scalar_types and isinstance(obj, scalar_types):
+            return True
+        try:
+            iter(obj)
+        except TypeError:
+            return True
+        else:
+            return False
+
+    size = len(objects)
+    if not size:
+        return
+
+    iterables, iterable_positions = [], []
+    scalars, scalar_positions = [], []
+    for i, obj in enumerate(objects):
+        if is_scalar(obj):
+            scalars.append(obj)
+            scalar_positions.append(i)
+        else:
+            iterables.append(iter(obj))
+            iterable_positions.append(i)
+
+    if len(scalars) == size:
+        yield tuple(objects)
+        return
+
+    zipper = _zip_equal if strict else zip
+    for item in zipper(*iterables):
+        new_item = [None] * size
+
+        for i, elem in zip(iterable_positions, item):
+            new_item[i] = elem
+
+        for i, elem in zip(scalar_positions, scalars):
+            new_item[i] = elem
+
+        yield tuple(new_item)
+
+
+def unique_in_window(iterable, n, key=None):
+    """Yield the items from *iterable* that haven't been seen recently.
+    *n* is the size of the lookback window.
+
+        >>> iterable = [0, 1, 0, 2, 3, 0]
+        >>> n = 3
+        >>> list(unique_in_window(iterable, n))
+        [0, 1, 2, 3, 0]
+
+    The *key* function, if provided, will be used to determine uniqueness:
+
+        >>> list(unique_in_window('abAcda', 3, key=lambda x: x.lower()))
+        ['a', 'b', 'c', 'd', 'a']
+
+    The items in *iterable* must be hashable.
+
+    """
+    if n <= 0:
+        raise ValueError('n must be greater than 0')
+
+    window = deque(maxlen=n)
+    uniques = set()
+    use_key = key is not None
+
+    for item in iterable:
+        k = key(item) if use_key else item
+        if k in uniques:
+            continue
+
+        if len(uniques) == n:
+            uniques.discard(window[0])
+
+        uniques.add(k)
+        window.append(k)
+
+        yield item
+
+
+def duplicates_everseen(iterable, key=None):
+    """Yield duplicate elements after their first appearance.
+
+    >>> list(duplicates_everseen('mississippi'))
+    ['s', 'i', 's', 's', 'i', 'p', 'i']
+    >>> list(duplicates_everseen('AaaBbbCccAaa', str.lower))
+    ['a', 'a', 'b', 'b', 'c', 'c', 'A', 'a', 'a']
+
+    This function is analagous to :func:`unique_everseen` and is subject to
+    the same performance considerations.
+
+    """
+    seen_set = set()
+    seen_list = []
+    use_key = key is not None
+
+    for element in iterable:
+        k = key(element) if use_key else element
+        try:
+            if k not in seen_set:
+                seen_set.add(k)
+            else:
+                yield element
+        except TypeError:
+            if k not in seen_list:
+                seen_list.append(k)
+            else:
+                yield element
+
+
+def duplicates_justseen(iterable, key=None):
+    """Yields serially-duplicate elements after their first appearance.
+
+    >>> list(duplicates_justseen('mississippi'))
+    ['s', 's', 'p']
+    >>> list(duplicates_justseen('AaaBbbCccAaa', str.lower))
+    ['a', 'a', 'b', 'b', 'c', 'c', 'a', 'a']
+
+    This function is analagous to :func:`unique_justseen`.
+
+    """
+    return flatten(
+        map(
+            lambda group_tuple: islice_extended(group_tuple[1])[1:],
+            groupby(iterable, key),
+        )
+    )
+
+
+def minmax(iterable_or_value, *others, key=None, default=_marker):
+    """Returns both the smallest and largest items in an iterable
+    or the largest of two or more arguments.
+
+        >>> minmax([3, 1, 5])
+        (1, 5)
+
+        >>> minmax(4, 2, 6)
+        (2, 6)
+
+    If a *key* function is provided, it will be used to transform the input
+    items for comparison.
+
+        >>> minmax([5, 30], key=str)  # '30' sorts before '5'
+        (30, 5)
+
+    If a *default* value is provided, it will be returned if there are no
+    input items.
+
+        >>> minmax([], default=(0, 0))
+        (0, 0)
+
+    Otherwise ``ValueError`` is raised.
+
+    This function is based on the
+    `recipe <http://code.activestate.com/recipes/577916/>`__ by
+    Raymond Hettinger and takes care to minimize the number of comparisons
+    performed.
+    """
+    iterable = (iterable_or_value, *others) if others else iterable_or_value
+
+    it = iter(iterable)
+
+    try:
+        lo = hi = next(it)
+    except StopIteration as e:
+        if default is _marker:
+            raise ValueError(
+                '`minmax()` argument is an empty iterable. '
+                'Provide a `default` value to suppress this error.'
+            ) from e
+        return default
+
+    # Different branches depending on the presence of key. This saves a lot
+    # of unimportant copies which would slow the "key=None" branch
+    # significantly down.
+    if key is None:
+        for x, y in zip_longest(it, it, fillvalue=lo):
+            if y < x:
+                x, y = y, x
+            if x < lo:
+                lo = x
+            if hi < y:
+                hi = y
+
+    else:
+        lo_key = hi_key = key(lo)
+
+        for x, y in zip_longest(it, it, fillvalue=lo):
+            x_key, y_key = key(x), key(y)
+
+            if y_key < x_key:
+                x, y, x_key, y_key = y, x, y_key, x_key
+            if x_key < lo_key:
+                lo, lo_key = x, x_key
+            if hi_key < y_key:
+                hi, hi_key = y, y_key
+
+    return lo, hi
+
+
+def constrained_batches(
+    iterable, max_size, max_count=None, get_len=len, strict=True
+):
+    """Yield batches of items from *iterable* with a combined size limited by
+    *max_size*.
+
+    >>> iterable = [b'12345', b'123', b'12345678', b'1', b'1', b'12', b'1']
+    >>> list(constrained_batches(iterable, 10))
+    [(b'12345', b'123'), (b'12345678', b'1', b'1'), (b'12', b'1')]
+
+    If a *max_count* is supplied, the number of items per batch is also
+    limited:
+
+    >>> iterable = [b'12345', b'123', b'12345678', b'1', b'1', b'12', b'1']
+    >>> list(constrained_batches(iterable, 10, max_count = 2))
+    [(b'12345', b'123'), (b'12345678', b'1'), (b'1', b'12'), (b'1',)]
+
+    If a *get_len* function is supplied, use that instead of :func:`len` to
+    determine item size.
+
+    If *strict* is ``True``, raise ``ValueError`` if any single item is bigger
+    than *max_size*. Otherwise, allow single items to exceed *max_size*.
+    """
+    if max_size <= 0:
+        raise ValueError('maximum size must be greater than zero')
+
+    batch = []
+    batch_size = 0
+    batch_count = 0
+    for item in iterable:
+        item_len = get_len(item)
+        if strict and item_len > max_size:
+            raise ValueError('item size exceeds maximum size')
+
+        reached_count = batch_count == max_count
+        reached_size = item_len + batch_size > max_size
+        if batch_count and (reached_size or reached_count):
+            yield tuple(batch)
+            batch.clear()
+            batch_size = 0
+            batch_count = 0
+
+        batch.append(item)
+        batch_size += item_len
+        batch_count += 1
+
+    if batch:
+        yield tuple(batch)
+
+
+def gray_product(*iterables):
+    """Like :func:`itertools.product`, but return tuples in an order such
+    that only one element in the generated tuple changes from one iteration
+    to the next.
+
+        >>> list(gray_product('AB','CD'))
+        [('A', 'C'), ('B', 'C'), ('B', 'D'), ('A', 'D')]
+
+    This function consumes all of the input iterables before producing output.
+    If any of the input iterables have fewer than two items, ``ValueError``
+    is raised.
+
+    For information on the algorithm, see
+    `this section <https://www-cs-faculty.stanford.edu/~knuth/fasc2a.ps.gz>`__
+    of Donald Knuth's *The Art of Computer Programming*.
+    """
+    all_iterables = tuple(tuple(x) for x in iterables)
+    iterable_count = len(all_iterables)
+    for iterable in all_iterables:
+        if len(iterable) < 2:
+            raise ValueError("each iterable must have two or more items")
+
+    # This is based on "Algorithm H" from section 7.2.1.1, page 20.
+    # a holds the indexes of the source iterables for the n-tuple to be yielded
+    # f is the array of "focus pointers"
+    # o is the array of "directions"
+    a = [0] * iterable_count
+    f = list(range(iterable_count + 1))
+    o = [1] * iterable_count
+    while True:
+        yield tuple(all_iterables[i][a[i]] for i in range(iterable_count))
+        j = f[0]
+        f[0] = 0
+        if j == iterable_count:
+            break
+        a[j] = a[j] + o[j]
+        if a[j] == 0 or a[j] == len(all_iterables[j]) - 1:
+            o[j] = -o[j]
+            f[j] = f[j + 1]
+            f[j + 1] = j + 1
diff --git a/third_party/python/setuptools/pkg_resources/_vendor/more_itertools/recipes.py b/third_party/python/setuptools/pkg_resources/_vendor/more_itertools/recipes.py
new file mode 100644
index 0000000000..3facc2e3a6
--- /dev/null
+++ b/third_party/python/setuptools/pkg_resources/_vendor/more_itertools/recipes.py
@@ -0,0 +1,930 @@
+"""Imported from the recipes section of the itertools documentation.
+
+All functions taken from the recipes section of the itertools library docs
+[1]_.
+Some backward-compatible usability improvements have been made.
+
+.. [1] http://docs.python.org/library/itertools.html#recipes
+
+"""
+import math
+import operator
+import warnings
+
+from collections import deque
+from collections.abc import Sized
+from functools import reduce
+from itertools import (
+    chain,
+    combinations,
+    compress,
+    count,
+    cycle,
+    groupby,
+    islice,
+    product,
+    repeat,
+    starmap,
+    tee,
+    zip_longest,
+)
+from random import randrange, sample, choice
+from sys import hexversion
+
+__all__ = [
+    'all_equal',
+    'batched',
+    'before_and_after',
+    'consume',
+    'convolve',
+    'dotproduct',
+    'first_true',
+    'factor',
+    'flatten',
+    'grouper',
+    'iter_except',
+    'iter_index',
+    'matmul',
+    'ncycles',
+    'nth',
+    'nth_combination',
+    'padnone',
+    'pad_none',
+    'pairwise',
+    'partition',
+    'polynomial_from_roots',
+    'powerset',
+    'prepend',
+    'quantify',
+    'random_combination_with_replacement',
+    'random_combination',
+    'random_permutation',
+    'random_product',
+    'repeatfunc',
+    'roundrobin',
+    'sieve',
+    'sliding_window',
+    'subslices',
+    'tabulate',
+    'tail',
+    'take',
+    'transpose',
+    'triplewise',
+    'unique_everseen',
+    'unique_justseen',
+]
+
+_marker = object()
+
+
+def take(n, iterable):
+    """Return first *n* items of the iterable as a list.
+
+        >>> take(3, range(10))
+        [0, 1, 2]
+
+    If there are fewer than *n* items in the iterable, all of them are
+    returned.
+
+        >>> take(10, range(3))
+        [0, 1, 2]
+
+    """
+    return list(islice(iterable, n))
+
+
+def tabulate(function, start=0):
+    """Return an iterator over the results of ``func(start)``,
+    ``func(start + 1)``, ``func(start + 2)``...
+
+    *func* should be a function that accepts one integer argument.
+
+    If *start* is not specified it defaults to 0. It will be incremented each
+    time the iterator is advanced.
+
+        >>> square = lambda x: x ** 2
+        >>> iterator = tabulate(square, -3)
+        >>> take(4, iterator)
+        [9, 4, 1, 0]
+
+    """
+    return map(function, count(start))
+
+
+def tail(n, iterable):
+    """Return an iterator over the last *n* items of *iterable*.
+
+    >>> t = tail(3, 'ABCDEFG')
+    >>> list(t)
+    ['E', 'F', 'G']
+
+    """
+    # If the given iterable has a length, then we can use islice to get its
+    # final elements. Note that if the iterable is not actually Iterable,
+    # either islice or deque will throw a TypeError. This is why we don't
+    # check if it is Iterable.
+    if isinstance(iterable, Sized):
+        yield from islice(iterable, max(0, len(iterable) - n), None)
+    else:
+        yield from iter(deque(iterable, maxlen=n))
+
+
+def consume(iterator, n=None):
+    """Advance *iterable* by *n* steps. If *n* is ``None``, consume it
+    entirely.
+
+    Efficiently exhausts an iterator without returning values. Defaults to
+    consuming the whole iterator, but an optional second argument may be
+    provided to limit consumption.
+
+        >>> i = (x for x in range(10))
+        >>> next(i)
+        0
+        >>> consume(i, 3)
+        >>> next(i)
+        4
+        >>> consume(i)
+        >>> next(i)
+        Traceback (most recent call last):
+          File "<stdin>", line 1, in <module>
+        StopIteration
+
+    If the iterator has fewer items remaining than the provided limit, the
+    whole iterator will be consumed.
+
+        >>> i = (x for x in range(3))
+        >>> consume(i, 5)
+        >>> next(i)
+        Traceback (most recent call last):
+          File "<stdin>", line 1, in <module>
+        StopIteration
+
+    """
+    # Use functions that consume iterators at C speed.
+    if n is None:
+        # feed the entire iterator into a zero-length deque
+        deque(iterator, maxlen=0)
+    else:
+        # advance to the empty slice starting at position n
+        next(islice(iterator, n, n), None)
+
+
+def nth(iterable, n, default=None):
+    """Returns the nth item or a default value.
+
+    >>> l = range(10)
+    >>> nth(l, 3)
+    3
+    >>> nth(l, 20, "zebra")
+    'zebra'
+
+    """
+    return next(islice(iterable, n, None), default)
+
+
+def all_equal(iterable):
+    """
+    Returns ``True`` if all the elements are equal to each other.
+
+        >>> all_equal('aaaa')
+        True
+        >>> all_equal('aaab')
+        False
+
+    """
+    g = groupby(iterable)
+    return next(g, True) and not next(g, False)
+
+
+def quantify(iterable, pred=bool):
+    """Return the how many times the predicate is true.
+
+    >>> quantify([True, False, True])
+    2
+
+    """
+    return sum(map(pred, iterable))
+
+
+def pad_none(iterable):
+    """Returns the sequence of elements and then returns ``None`` indefinitely.
+
+        >>> take(5, pad_none(range(3)))
+        [0, 1, 2, None, None]
+
+    Useful for emulating the behavior of the built-in :func:`map` function.
+
+    See also :func:`padded`.
+
+    """
+    return chain(iterable, repeat(None))
+
+
+padnone = pad_none
+
+
+def ncycles(iterable, n):
+    """Returns the sequence elements *n* times
+
+    >>> list(ncycles(["a", "b"], 3))
+    ['a', 'b', 'a', 'b', 'a', 'b']
+
+    """
+    return chain.from_iterable(repeat(tuple(iterable), n))
+
+
+def dotproduct(vec1, vec2):
+    """Returns the dot product of the two iterables.
+
+    >>> dotproduct([10, 10], [20, 20])
+    400
+
+    """
+    return sum(map(operator.mul, vec1, vec2))
+
+
+def flatten(listOfLists):
+    """Return an iterator flattening one level of nesting in a list of lists.
+
+        >>> list(flatten([[0, 1], [2, 3]]))
+        [0, 1, 2, 3]
+
+    See also :func:`collapse`, which can flatten multiple levels of nesting.
+
+    """
+    return chain.from_iterable(listOfLists)
+
+
+def repeatfunc(func, times=None, *args):
+    """Call *func* with *args* repeatedly, returning an iterable over the
+    results.
+
+    If *times* is specified, the iterable will terminate after that many
+    repetitions:
+
+        >>> from operator import add
+        >>> times = 4
+        >>> args = 3, 5
+        >>> list(repeatfunc(add, times, *args))
+        [8, 8, 8, 8]
+
+    If *times* is ``None`` the iterable will not terminate:
+
+        >>> from random import randrange
+        >>> times = None
+        >>> args = 1, 11
+        >>> take(6, repeatfunc(randrange, times, *args))  # doctest:+SKIP
+        [2, 4, 8, 1, 8, 4]
+
+    """
+    if times is None:
+        return starmap(func, repeat(args))
+    return starmap(func, repeat(args, times))
+
+
+def _pairwise(iterable):
+    """Returns an iterator of paired items, overlapping, from the original
+
+    >>> take(4, pairwise(count()))
+    [(0, 1), (1, 2), (2, 3), (3, 4)]
+
+    On Python 3.10 and above, this is an alias for :func:`itertools.pairwise`.
+
+    """
+    a, b = tee(iterable)
+    next(b, None)
+    yield from zip(a, b)
+
+
+try:
+    from itertools import pairwise as itertools_pairwise
+except ImportError:
+    pairwise = _pairwise
+else:
+
+    def pairwise(iterable):
+        yield from itertools_pairwise(iterable)
+
+    pairwise.__doc__ = _pairwise.__doc__
+
+
+class UnequalIterablesError(ValueError):
+    def __init__(self, details=None):
+        msg = 'Iterables have different lengths'
+        if details is not None:
+            msg += (': index 0 has length {}; index {} has length {}').format(
+                *details
+            )
+
+        super().__init__(msg)
+
+
+def _zip_equal_generator(iterables):
+    for combo in zip_longest(*iterables, fillvalue=_marker):
+        for val in combo:
+            if val is _marker:
+                raise UnequalIterablesError()
+        yield combo
+
+
+def _zip_equal(*iterables):
+    # Check whether the iterables are all the same size.
+    try:
+        first_size = len(iterables[0])
+        for i, it in enumerate(iterables[1:], 1):
+            size = len(it)
+            if size != first_size:
+                break
+        else:
+            # If we didn't break out, we can use the built-in zip.
+            return zip(*iterables)
+
+        # If we did break out, there was a mismatch.
+        raise UnequalIterablesError(details=(first_size, i, size))
+    # If any one of the iterables didn't have a length, start reading
+    # them until one runs out.
+    except TypeError:
+        return _zip_equal_generator(iterables)
+
+
+def grouper(iterable, n, incomplete='fill', fillvalue=None):
+    """Group elements from *iterable* into fixed-length groups of length *n*.
+
+    >>> list(grouper('ABCDEF', 3))
+    [('A', 'B', 'C'), ('D', 'E', 'F')]
+
+    The keyword arguments *incomplete* and *fillvalue* control what happens for
+    iterables whose length is not a multiple of *n*.
+
+    When *incomplete* is `'fill'`, the last group will contain instances of
+    *fillvalue*.
+
+    >>> list(grouper('ABCDEFG', 3, incomplete='fill', fillvalue='x'))
+    [('A', 'B', 'C'), ('D', 'E', 'F'), ('G', 'x', 'x')]
+
+    When *incomplete* is `'ignore'`, the last group will not be emitted.
+
+    >>> list(grouper('ABCDEFG', 3, incomplete='ignore', fillvalue='x'))
+    [('A', 'B', 'C'), ('D', 'E', 'F')]
+
+    When *incomplete* is `'strict'`, a subclass of `ValueError` will be raised.
+
+    >>> it = grouper('ABCDEFG', 3, incomplete='strict')
+    >>> list(it)  # doctest: +IGNORE_EXCEPTION_DETAIL
+    Traceback (most recent call last):
+    ...
+    UnequalIterablesError
+
+    """
+    args = [iter(iterable)] * n
+    if incomplete == 'fill':
+        return zip_longest(*args, fillvalue=fillvalue)
+    if incomplete == 'strict':
+        return _zip_equal(*args)
+    if incomplete == 'ignore':
+        return zip(*args)
+    else:
+        raise ValueError('Expected fill, strict, or ignore')
+
+
+def roundrobin(*iterables):
+    """Yields an item from each iterable, alternating between them.
+
+        >>> list(roundrobin('ABC', 'D', 'EF'))
+        ['A', 'D', 'E', 'B', 'F', 'C']
+
+    This function produces the same output as :func:`interleave_longest`, but
+    may perform better for some inputs (in particular when the number of
+    iterables is small).
+
+    """
+    # Recipe credited to George Sakkis
+    pending = len(iterables)
+    nexts = cycle(iter(it).__next__ for it in iterables)
+    while pending:
+        try:
+            for next in nexts:
+                yield next()
+        except StopIteration:
+            pending -= 1
+            nexts = cycle(islice(nexts, pending))
+
+
+def partition(pred, iterable):
+    """
+    Returns a 2-tuple of iterables derived from the input iterable.
+    The first yields the items that have ``pred(item) == False``.
+    The second yields the items that have ``pred(item) == True``.
+
+        >>> is_odd = lambda x: x % 2 != 0
+        >>> iterable = range(10)
+        >>> even_items, odd_items = partition(is_odd, iterable)
+        >>> list(even_items), list(odd_items)
+        ([0, 2, 4, 6, 8], [1, 3, 5, 7, 9])
+
+    If *pred* is None, :func:`bool` is used.
+
+        >>> iterable = [0, 1, False, True, '', ' ']
+        >>> false_items, true_items = partition(None, iterable)
+        >>> list(false_items), list(true_items)
+        ([0, False, ''], [1, True, ' '])
+
+    """
+    if pred is None:
+        pred = bool
+
+    evaluations = ((pred(x), x) for x in iterable)
+    t1, t2 = tee(evaluations)
+    return (
+        (x for (cond, x) in t1 if not cond),
+        (x for (cond, x) in t2 if cond),
+    )
+
+
+def powerset(iterable):
+    """Yields all possible subsets of the iterable.
+
+        >>> list(powerset([1, 2, 3]))
+        [(), (1,), (2,), (3,), (1, 2), (1, 3), (2, 3), (1, 2, 3)]
+
+    :func:`powerset` will operate on iterables that aren't :class:`set`
+    instances, so repeated elements in the input will produce repeated elements
+    in the output. Use :func:`unique_everseen` on the input to avoid generating
+    duplicates:
+
+        >>> seq = [1, 1, 0]
+        >>> list(powerset(seq))
+        [(), (1,), (1,), (0,), (1, 1), (1, 0), (1, 0), (1, 1, 0)]
+        >>> from more_itertools import unique_everseen
+        >>> list(powerset(unique_everseen(seq)))
+        [(), (1,), (0,), (1, 0)]
+
+    """
+    s = list(iterable)
+    return chain.from_iterable(combinations(s, r) for r in range(len(s) + 1))
+
+
+def unique_everseen(iterable, key=None):
+    """
+    Yield unique elements, preserving order.
+
+        >>> list(unique_everseen('AAAABBBCCDAABBB'))
+        ['A', 'B', 'C', 'D']
+        >>> list(unique_everseen('ABBCcAD', str.lower))
+        ['A', 'B', 'C', 'D']
+
+    Sequences with a mix of hashable and unhashable items can be used.
+    The function will be slower (i.e., `O(n^2)`) for unhashable items.
+
+    Remember that ``list`` objects are unhashable - you can use the *key*
+    parameter to transform the list to a tuple (which is hashable) to
+    avoid a slowdown.
+
+        >>> iterable = ([1, 2], [2, 3], [1, 2])
+        >>> list(unique_everseen(iterable))  # Slow
+        [[1, 2], [2, 3]]
+        >>> list(unique_everseen(iterable, key=tuple))  # Faster
+        [[1, 2], [2, 3]]
+
+    Similary, you may want to convert unhashable ``set`` objects with
+    ``key=frozenset``. For ``dict`` objects,
+    ``key=lambda x: frozenset(x.items())`` can be used.
+
+    """
+    seenset = set()
+    seenset_add = seenset.add
+    seenlist = []
+    seenlist_add = seenlist.append
+    use_key = key is not None
+
+    for element in iterable:
+        k = key(element) if use_key else element
+        try:
+            if k not in seenset:
+                seenset_add(k)
+                yield element
+        except TypeError:
+            if k not in seenlist:
+                seenlist_add(k)
+                yield element
+
+
+def unique_justseen(iterable, key=None):
+    """Yields elements in order, ignoring serial duplicates
+
+    >>> list(unique_justseen('AAAABBBCCDAABBB'))
+    ['A', 'B', 'C', 'D', 'A', 'B']
+    >>> list(unique_justseen('ABBCcAD', str.lower))
+    ['A', 'B', 'C', 'A', 'D']
+
+    """
+    return map(next, map(operator.itemgetter(1), groupby(iterable, key)))
+
+
+def iter_except(func, exception, first=None):
+    """Yields results from a function repeatedly until an exception is raised.
+
+    Converts a call-until-exception interface to an iterator interface.
+    Like ``iter(func, sentinel)``, but uses an exception instead of a sentinel
+    to end the loop.
+
+        >>> l = [0, 1, 2]
+        >>> list(iter_except(l.pop, IndexError))
+        [2, 1, 0]
+
+    Multiple exceptions can be specified as a stopping condition:
+
+        >>> l = [1, 2, 3, '...', 4, 5, 6]
+        >>> list(iter_except(lambda: 1 + l.pop(), (IndexError, TypeError)))
+        [7, 6, 5]
+        >>> list(iter_except(lambda: 1 + l.pop(), (IndexError, TypeError)))
+        [4, 3, 2]
+        >>> list(iter_except(lambda: 1 + l.pop(), (IndexError, TypeError)))
+        []
+
+    """
+    try:
+        if first is not None:
+            yield first()
+        while 1:
+            yield func()
+    except exception:
+        pass
+
+
+def first_true(iterable, default=None, pred=None):
+    """
+    Returns the first true value in the iterable.
+
+    If no true value is found, returns *default*
+
+    If *pred* is not None, returns the first item for which
+    ``pred(item) == True`` .
+
+        >>> first_true(range(10))
+        1
+        >>> first_true(range(10), pred=lambda x: x > 5)
+        6
+        >>> first_true(range(10), default='missing', pred=lambda x: x > 9)
+        'missing'
+
+    """
+    return next(filter(pred, iterable), default)
+
+
+def random_product(*args, repeat=1):
+    """Draw an item at random from each of the input iterables.
+
+        >>> random_product('abc', range(4), 'XYZ')  # doctest:+SKIP
+        ('c', 3, 'Z')
+
+    If *repeat* is provided as a keyword argument, that many items will be
+    drawn from each iterable.
+
+        >>> random_product('abcd', range(4), repeat=2)  # doctest:+SKIP
+        ('a', 2, 'd', 3)
+
+    This equivalent to taking a random selection from
+    ``itertools.product(*args, **kwarg)``.
+
+    """
+    pools = [tuple(pool) for pool in args] * repeat
+    return tuple(choice(pool) for pool in pools)
+
+
+def random_permutation(iterable, r=None):
+    """Return a random *r* length permutation of the elements in *iterable*.
+
+    If *r* is not specified or is ``None``, then *r* defaults to the length of
+    *iterable*.
+
+        >>> random_permutation(range(5))  # doctest:+SKIP
+        (3, 4, 0, 1, 2)
+
+    This equivalent to taking a random selection from
+    ``itertools.permutations(iterable, r)``.
+
+    """
+    pool = tuple(iterable)
+    r = len(pool) if r is None else r
+    return tuple(sample(pool, r))
+
+
+def random_combination(iterable, r):
+    """Return a random *r* length subsequence of the elements in *iterable*.
+
+        >>> random_combination(range(5), 3)  # doctest:+SKIP
+        (2, 3, 4)
+
+    This equivalent to taking a random selection from
+    ``itertools.combinations(iterable, r)``.
+
+    """
+    pool = tuple(iterable)
+    n = len(pool)
+    indices = sorted(sample(range(n), r))
+    return tuple(pool[i] for i in indices)
+
+
+def random_combination_with_replacement(iterable, r):
+    """Return a random *r* length subsequence of elements in *iterable*,
+    allowing individual elements to be repeated.
+
+        >>> random_combination_with_replacement(range(3), 5) # doctest:+SKIP
+        (0, 0, 1, 2, 2)
+
+    This equivalent to taking a random selection from
+    ``itertools.combinations_with_replacement(iterable, r)``.
+
+    """
+    pool = tuple(iterable)
+    n = len(pool)
+    indices = sorted(randrange(n) for i in range(r))
+    return tuple(pool[i] for i in indices)
+
+
+def nth_combination(iterable, r, index):
+    """Equivalent to ``list(combinations(iterable, r))[index]``.
+
+    The subsequences of *iterable* that are of length *r* can be ordered
+    lexicographically. :func:`nth_combination` computes the subsequence at
+    sort position *index* directly, without computing the previous
+    subsequences.
+
+        >>> nth_combination(range(5), 3, 5)
+        (0, 3, 4)
+
+    ``ValueError`` will be raised If *r* is negative or greater than the length
+    of *iterable*.
+    ``IndexError`` will be raised if the given *index* is invalid.
+    """
+    pool = tuple(iterable)
+    n = len(pool)
+    if (r < 0) or (r > n):
+        raise ValueError
+
+    c = 1
+    k = min(r, n - r)
+    for i in range(1, k + 1):
+        c = c * (n - k + i) // i
+
+    if index < 0:
+        index += c
+
+    if (index < 0) or (index >= c):
+        raise IndexError
+
+    result = []
+    while r:
+        c, n, r = c * r // n, n - 1, r - 1
+        while index >= c:
+            index -= c
+            c, n = c * (n - r) // n, n - 1
+        result.append(pool[-1 - n])
+
+    return tuple(result)
+
+
+def prepend(value, iterator):
+    """Yield *value*, followed by the elements in *iterator*.
+
+        >>> value = '0'
+        >>> iterator = ['1', '2', '3']
+        >>> list(prepend(value, iterator))
+        ['0', '1', '2', '3']
+
+    To prepend multiple values, see :func:`itertools.chain`
+    or :func:`value_chain`.
+
+    """
+    return chain([value], iterator)
+
+
+def convolve(signal, kernel):
+    """Convolve the iterable *signal* with the iterable *kernel*.
+
+        >>> signal = (1, 2, 3, 4, 5)
+        >>> kernel = [3, 2, 1]
+        >>> list(convolve(signal, kernel))
+        [3, 8, 14, 20, 26, 14, 5]
+
+    Note: the input arguments are not interchangeable, as the *kernel*
+    is immediately consumed and stored.
+
+    """
+    kernel = tuple(kernel)[::-1]
+    n = len(kernel)
+    window = deque([0], maxlen=n) * n
+    for x in chain(signal, repeat(0, n - 1)):
+        window.append(x)
+        yield sum(map(operator.mul, kernel, window))
+
+
+def before_and_after(predicate, it):
+    """A variant of :func:`takewhile` that allows complete access to the
+    remainder of the iterator.
+
+         >>> it = iter('ABCdEfGhI')
+         >>> all_upper, remainder = before_and_after(str.isupper, it)
+         >>> ''.join(all_upper)
+         'ABC'
+         >>> ''.join(remainder) # takewhile() would lose the 'd'
+         'dEfGhI'
+
+    Note that the first iterator must be fully consumed before the second
+    iterator can generate valid results.
+    """
+    it = iter(it)
+    transition = []
+
+    def true_iterator():
+        for elem in it:
+            if predicate(elem):
+                yield elem
+            else:
+                transition.append(elem)
+                return
+
+    # Note: this is different from itertools recipes to allow nesting
+    # before_and_after remainders into before_and_after again. See tests
+    # for an example.
+    remainder_iterator = chain(transition, it)
+
+    return true_iterator(), remainder_iterator
+
+
+def triplewise(iterable):
+    """Return overlapping triplets from *iterable*.
+
+    >>> list(triplewise('ABCDE'))
+    [('A', 'B', 'C'), ('B', 'C', 'D'), ('C', 'D', 'E')]
+
+    """
+    for (a, _), (b, c) in pairwise(pairwise(iterable)):
+        yield a, b, c
+
+
+def sliding_window(iterable, n):
+    """Return a sliding window of width *n* over *iterable*.
+
+        >>> list(sliding_window(range(6), 4))
+        [(0, 1, 2, 3), (1, 2, 3, 4), (2, 3, 4, 5)]
+
+    If *iterable* has fewer than *n* items, then nothing is yielded:
+
+        >>> list(sliding_window(range(3), 4))
+        []
+
+    For a variant with more features, see :func:`windowed`.
+    """
+    it = iter(iterable)
+    window = deque(islice(it, n), maxlen=n)
+    if len(window) == n:
+        yield tuple(window)
+    for x in it:
+        window.append(x)
+        yield tuple(window)
+
+
+def subslices(iterable):
+    """Return all contiguous non-empty subslices of *iterable*.
+
+        >>> list(subslices('ABC'))
+        [['A'], ['A', 'B'], ['A', 'B', 'C'], ['B'], ['B', 'C'], ['C']]
+
+    This is similar to :func:`substrings`, but emits items in a different
+    order.
+    """
+    seq = list(iterable)
+    slices = starmap(slice, combinations(range(len(seq) + 1), 2))
+    return map(operator.getitem, repeat(seq), slices)
+
+
+def polynomial_from_roots(roots):
+    """Compute a polynomial's coefficients from its roots.
+
+    >>> roots = [5, -4, 3]  # (x - 5) * (x + 4) * (x - 3)
+    >>> polynomial_from_roots(roots)  # x^3 - 4 * x^2 - 17 * x + 60
+    [1, -4, -17, 60]
+    """
+    # Use math.prod for Python 3.8+,
+    prod = getattr(math, 'prod', lambda x: reduce(operator.mul, x, 1))
+    roots = list(map(operator.neg, roots))
+    return [
+        sum(map(prod, combinations(roots, k))) for k in range(len(roots) + 1)
+    ]
+
+
+def iter_index(iterable, value, start=0):
+    """Yield the index of each place in *iterable* that *value* occurs,
+    beginning with index *start*.
+
+    See :func:`locate` for a more general means of finding the indexes
+    associated with particular values.
+
+    >>> list(iter_index('AABCADEAF', 'A'))
+    [0, 1, 4, 7]
+    """
+    try:
+        seq_index = iterable.index
+    except AttributeError:
+        # Slow path for general iterables
+        it = islice(iterable, start, None)
+        for i, element in enumerate(it, start):
+            if element is value or element == value:
+                yield i
+    else:
+        # Fast path for sequences
+        i = start - 1
+        try:
+            while True:
+                i = seq_index(value, i + 1)
+                yield i
+        except ValueError:
+            pass
+
+
+def sieve(n):
+    """Yield the primes less than n.
+
+    >>> list(sieve(30))
+    [2, 3, 5, 7, 11, 13, 17, 19, 23, 29]
+    """
+    isqrt = getattr(math, 'isqrt', lambda x: int(math.sqrt(x)))
+    data = bytearray((0, 1)) * (n // 2)
+    data[:3] = 0, 0, 0
+    limit = isqrt(n) + 1
+    for p in compress(range(limit), data):
+        data[p * p : n : p + p] = bytes(len(range(p * p, n, p + p)))
+    data[2] = 1
+    return iter_index(data, 1) if n > 2 else iter([])
+
+
+def batched(iterable, n):
+    """Batch data into lists of length *n*. The last batch may be shorter.
+
+    >>> list(batched('ABCDEFG', 3))
+    [['A', 'B', 'C'], ['D', 'E', 'F'], ['G']]
+
+    This recipe is from the ``itertools`` docs. This library also provides
+    :func:`chunked`, which has a different implementation.
+    """
+    if hexversion >= 0x30C00A0:  # Python 3.12.0a0
+        warnings.warn(
+            (
+                'batched will be removed in a future version of '
+                'more-itertools. Use the standard library '
+                'itertools.batched function instead'
+            ),
+            DeprecationWarning,
+        )
+
+    it = iter(iterable)
+    while True:
+        batch = list(islice(it, n))
+        if not batch:
+            break
+        yield batch
+
+
+def transpose(it):
+    """Swap the rows and columns of the input.
+
+    >>> list(transpose([(1, 2, 3), (11, 22, 33)]))
+    [(1, 11), (2, 22), (3, 33)]
+
+    The caller should ensure that the dimensions of the input are compatible.
+    """
+    # TODO: when 3.9 goes end-of-life, add stric=True to this.
+    return zip(*it)
+
+
+def matmul(m1, m2):
+    """Multiply two matrices.
+    >>> list(matmul([(7, 5), (3, 5)], [(2, 5), (7, 9)]))
+    [[49, 80], [41, 60]]
+
+    The caller should ensure that the dimensions of the input matrices are
+    compatible with each other.
+    """
+    n = len(m2[0])
+    return batched(starmap(dotproduct, product(m1, transpose(m2))), n)
+
+
+def factor(n):
+    """Yield the prime factors of n.
+    >>> list(factor(360))
+    [2, 2, 2, 3, 3, 5]
+    """
+    isqrt = getattr(math, 'isqrt', lambda x: int(math.sqrt(x)))
+    for prime in sieve(isqrt(n) + 1):
+        while True:
+            quotient, remainder = divmod(n, prime)
+            if remainder:
+                break
+            yield prime
+            n = quotient
+            if n == 1:
+                return
+    if n >= 2:
+        yield n
diff --git a/third_party/python/setuptools/pkg_resources/_vendor/packaging/__init__.py b/third_party/python/setuptools/pkg_resources/_vendor/packaging/__init__.py
new file mode 100644
index 0000000000..13cadc7f04
--- /dev/null
+++ b/third_party/python/setuptools/pkg_resources/_vendor/packaging/__init__.py
@@ -0,0 +1,15 @@
+# This file is dual licensed under the terms of the Apache License, Version
+# 2.0, and the BSD License. See the LICENSE file in the root of this repository
+# for complete details.
+
+__title__ = "packaging"
+__summary__ = "Core utilities for Python packages"
+__uri__ = "https://github.com/pypa/packaging"
+
+__version__ = "23.1"
+
+__author__ = "Donald Stufft and individual contributors"
+__email__ = "donald@stufft.io"
+
+__license__ = "BSD-2-Clause or Apache-2.0"
+__copyright__ = "2014-2019 %s" % __author__
diff --git a/third_party/python/setuptools/pkg_resources/_vendor/packaging/_elffile.py b/third_party/python/setuptools/pkg_resources/_vendor/packaging/_elffile.py
new file mode 100644
index 0000000000..6fb19b30bb
--- /dev/null
+++ b/third_party/python/setuptools/pkg_resources/_vendor/packaging/_elffile.py
@@ -0,0 +1,108 @@
+"""
+ELF file parser.
+
+This provides a class ``ELFFile`` that parses an ELF executable in a similar
+interface to ``ZipFile``. Only the read interface is implemented.
+
+Based on: https://gist.github.com/lyssdod/f51579ae8d93c8657a5564aefc2ffbca
+ELF header: https://refspecs.linuxfoundation.org/elf/gabi4+/ch4.eheader.html
+"""
+
+import enum
+import os
+import struct
+from typing import IO, Optional, Tuple
+
+
+class ELFInvalid(ValueError):
+    pass
+
+
+class EIClass(enum.IntEnum):
+    C32 = 1
+    C64 = 2
+
+
+class EIData(enum.IntEnum):
+    Lsb = 1
+    Msb = 2
+
+
+class EMachine(enum.IntEnum):
+    I386 = 3
+    S390 = 22
+    Arm = 40
+    X8664 = 62
+    AArc64 = 183
+
+
+class ELFFile:
+    """
+    Representation of an ELF executable.
+    """
+
+    def __init__(self, f: IO[bytes]) -> None:
+        self._f = f
+
+        try:
+            ident = self._read("16B")
+        except struct.error:
+            raise ELFInvalid("unable to parse identification")
+        magic = bytes(ident[:4])
+        if magic != b"\x7fELF":
+            raise ELFInvalid(f"invalid magic: {magic!r}")
+
+        self.capacity = ident[4]  # Format for program header (bitness).
+        self.encoding = ident[5]  # Data structure encoding (endianness).
+
+        try:
+            # e_fmt: Format for program header.
+            # p_fmt: Format for section header.
+            # p_idx: Indexes to find p_type, p_offset, and p_filesz.
+            e_fmt, self._p_fmt, self._p_idx = {
+                (1, 1): ("<HHIIIIIHHH", "<IIIIIIII", (0, 1, 4)),  # 32-bit LSB.
+                (1, 2): (">HHIIIIIHHH", ">IIIIIIII", (0, 1, 4)),  # 32-bit MSB.
+                (2, 1): ("<HHIQQQIHHH", "<IIQQQQQQ", (0, 2, 5)),  # 64-bit LSB.
+                (2, 2): (">HHIQQQIHHH", ">IIQQQQQQ", (0, 2, 5)),  # 64-bit MSB.
+            }[(self.capacity, self.encoding)]
+        except KeyError:
+            raise ELFInvalid(
+                f"unrecognized capacity ({self.capacity}) or "
+                f"encoding ({self.encoding})"
+            )
+
+        try:
+            (
+                _,
+                self.machine,  # Architecture type.
+                _,
+                _,
+                self._e_phoff,  # Offset of program header.
+                _,
+                self.flags,  # Processor-specific flags.
+                _,
+                self._e_phentsize,  # Size of section.
+                self._e_phnum,  # Number of sections.
+            ) = self._read(e_fmt)
+        except struct.error as e:
+            raise ELFInvalid("unable to parse machine and section information") from e
+
+    def _read(self, fmt: str) -> Tuple[int, ...]:
+        return struct.unpack(fmt, self._f.read(struct.calcsize(fmt)))
+
+    @property
+    def interpreter(self) -> Optional[str]:
+        """
+        The path recorded in the ``PT_INTERP`` section header.
+        """
+        for index in range(self._e_phnum):
+            self._f.seek(self._e_phoff + self._e_phentsize * index)
+            try:
+                data = self._read(self._p_fmt)
+            except struct.error:
+                continue
+            if data[self._p_idx[0]] != 3:  # Not PT_INTERP.
+                continue
+            self._f.seek(data[self._p_idx[1]])
+            return os.fsdecode(self._f.read(data[self._p_idx[2]])).strip("\0")
+        return None
diff --git a/third_party/python/setuptools/pkg_resources/_vendor/packaging/_manylinux.py b/third_party/python/setuptools/pkg_resources/_vendor/packaging/_manylinux.py
new file mode 100644
index 0000000000..449c655be6
--- /dev/null
+++ b/third_party/python/setuptools/pkg_resources/_vendor/packaging/_manylinux.py
@@ -0,0 +1,240 @@
+import collections
+import contextlib
+import functools
+import os
+import re
+import sys
+import warnings
+from typing import Dict, Generator, Iterator, NamedTuple, Optional, Tuple
+
+from ._elffile import EIClass, EIData, ELFFile, EMachine
+
+EF_ARM_ABIMASK = 0xFF000000
+EF_ARM_ABI_VER5 = 0x05000000
+EF_ARM_ABI_FLOAT_HARD = 0x00000400
+
+
+# `os.PathLike` not a generic type until Python 3.9, so sticking with `str`
+# as the type for `path` until then.
+@contextlib.contextmanager
+def _parse_elf(path: str) -> Generator[Optional[ELFFile], None, None]:
+    try:
+        with open(path, "rb") as f:
+            yield ELFFile(f)
+    except (OSError, TypeError, ValueError):
+        yield None
+
+
+def _is_linux_armhf(executable: str) -> bool:
+    # hard-float ABI can be detected from the ELF header of the running
+    # process
+    # https://static.docs.arm.com/ihi0044/g/aaelf32.pdf
+    with _parse_elf(executable) as f:
+        return (
+            f is not None
+            and f.capacity == EIClass.C32
+            and f.encoding == EIData.Lsb
+            and f.machine == EMachine.Arm
+            and f.flags & EF_ARM_ABIMASK == EF_ARM_ABI_VER5
+            and f.flags & EF_ARM_ABI_FLOAT_HARD == EF_ARM_ABI_FLOAT_HARD
+        )
+
+
+def _is_linux_i686(executable: str) -> bool:
+    with _parse_elf(executable) as f:
+        return (
+            f is not None
+            and f.capacity == EIClass.C32
+            and f.encoding == EIData.Lsb
+            and f.machine == EMachine.I386
+        )
+
+
+def _have_compatible_abi(executable: str, arch: str) -> bool:
+    if arch == "armv7l":
+        return _is_linux_armhf(executable)
+    if arch == "i686":
+        return _is_linux_i686(executable)
+    return arch in {"x86_64", "aarch64", "ppc64", "ppc64le", "s390x"}
+
+
+# If glibc ever changes its major version, we need to know what the last
+# minor version was, so we can build the complete list of all versions.
+# For now, guess what the highest minor version might be, assume it will
+# be 50 for testing. Once this actually happens, update the dictionary
+# with the actual value.
+_LAST_GLIBC_MINOR: Dict[int, int] = collections.defaultdict(lambda: 50)
+
+
+class _GLibCVersion(NamedTuple):
+    major: int
+    minor: int
+
+
+def _glibc_version_string_confstr() -> Optional[str]:
+    """
+    Primary implementation of glibc_version_string using os.confstr.
+    """
+    # os.confstr is quite a bit faster than ctypes.DLL. It's also less likely
+    # to be broken or missing. This strategy is used in the standard library
+    # platform module.
+    # https://github.com/python/cpython/blob/fcf1d003bf4f0100c/Lib/platform.py#L175-L183
+    try:
+        # Should be a string like "glibc 2.17".
+        version_string: str = getattr(os, "confstr")("CS_GNU_LIBC_VERSION")
+        assert version_string is not None
+        _, version = version_string.rsplit()
+    except (AssertionError, AttributeError, OSError, ValueError):
+        # os.confstr() or CS_GNU_LIBC_VERSION not available (or a bad value)...
+        return None
+    return version
+
+
+def _glibc_version_string_ctypes() -> Optional[str]:
+    """
+    Fallback implementation of glibc_version_string using ctypes.
+    """
+    try:
+        import ctypes
+    except ImportError:
+        return None
+
+    # ctypes.CDLL(None) internally calls dlopen(NULL), and as the dlopen
+    # manpage says, "If filename is NULL, then the returned handle is for the
+    # main program". This way we can let the linker do the work to figure out
+    # which libc our process is actually using.
+    #
+    # We must also handle the special case where the executable is not a
+    # dynamically linked executable. This can occur when using musl libc,
+    # for example. In this situation, dlopen() will error, leading to an
+    # OSError. Interestingly, at least in the case of musl, there is no
+    # errno set on the OSError. The single string argument used to construct
+    # OSError comes from libc itself and is therefore not portable to
+    # hard code here. In any case, failure to call dlopen() means we
+    # can proceed, so we bail on our attempt.
+    try:
+        process_namespace = ctypes.CDLL(None)
+    except OSError:
+        return None
+
+    try:
+        gnu_get_libc_version = process_namespace.gnu_get_libc_version
+    except AttributeError:
+        # Symbol doesn't exist -> therefore, we are not linked to
+        # glibc.
+        return None
+
+    # Call gnu_get_libc_version, which returns a string like "2.5"
+    gnu_get_libc_version.restype = ctypes.c_char_p
+    version_str: str = gnu_get_libc_version()
+    # py2 / py3 compatibility:
+    if not isinstance(version_str, str):
+        version_str = version_str.decode("ascii")
+
+    return version_str
+
+
+def _glibc_version_string() -> Optional[str]:
+    """Returns glibc version string, or None if not using glibc."""
+    return _glibc_version_string_confstr() or _glibc_version_string_ctypes()
+
+
+def _parse_glibc_version(version_str: str) -> Tuple[int, int]:
+    """Parse glibc version.
+
+    We use a regexp instead of str.split because we want to discard any
+    random junk that might come after the minor version -- this might happen
+    in patched/forked versions of glibc (e.g. Linaro's version of glibc
+    uses version strings like "2.20-2014.11"). See gh-3588.
+    """
+    m = re.match(r"(?P<major>[0-9]+)\.(?P<minor>[0-9]+)", version_str)
+    if not m:
+        warnings.warn(
+            f"Expected glibc version with 2 components major.minor,"
+            f" got: {version_str}",
+            RuntimeWarning,
+        )
+        return -1, -1
+    return int(m.group("major")), int(m.group("minor"))
+
+
+@functools.lru_cache()
+def _get_glibc_version() -> Tuple[int, int]:
+    version_str = _glibc_version_string()
+    if version_str is None:
+        return (-1, -1)
+    return _parse_glibc_version(version_str)
+
+
+# From PEP 513, PEP 600
+def _is_compatible(name: str, arch: str, version: _GLibCVersion) -> bool:
+    sys_glibc = _get_glibc_version()
+    if sys_glibc < version:
+        return False
+    # Check for presence of _manylinux module.
+    try:
+        import _manylinux  # noqa
+    except ImportError:
+        return True
+    if hasattr(_manylinux, "manylinux_compatible"):
+        result = _manylinux.manylinux_compatible(version[0], version[1], arch)
+        if result is not None:
+            return bool(result)
+        return True
+    if version == _GLibCVersion(2, 5):
+        if hasattr(_manylinux, "manylinux1_compatible"):
+            return bool(_manylinux.manylinux1_compatible)
+    if version == _GLibCVersion(2, 12):
+        if hasattr(_manylinux, "manylinux2010_compatible"):
+            return bool(_manylinux.manylinux2010_compatible)
+    if version == _GLibCVersion(2, 17):
+        if hasattr(_manylinux, "manylinux2014_compatible"):
+            return bool(_manylinux.manylinux2014_compatible)
+    return True
+
+
+_LEGACY_MANYLINUX_MAP = {
+    # CentOS 7 w/ glibc 2.17 (PEP 599)
+    (2, 17): "manylinux2014",
+    # CentOS 6 w/ glibc 2.12 (PEP 571)
+    (2, 12): "manylinux2010",
+    # CentOS 5 w/ glibc 2.5 (PEP 513)
+    (2, 5): "manylinux1",
+}
+
+
+def platform_tags(linux: str, arch: str) -> Iterator[str]:
+    if not _have_compatible_abi(sys.executable, arch):
+        return
+    # Oldest glibc to be supported regardless of architecture is (2, 17).
+    too_old_glibc2 = _GLibCVersion(2, 16)
+    if arch in {"x86_64", "i686"}:
+        # On x86/i686 also oldest glibc to be supported is (2, 5).
+        too_old_glibc2 = _GLibCVersion(2, 4)
+    current_glibc = _GLibCVersion(*_get_glibc_version())
+    glibc_max_list = [current_glibc]
+    # We can assume compatibility across glibc major versions.
+    # https://sourceware.org/bugzilla/show_bug.cgi?id=24636
+    #
+    # Build a list of maximum glibc versions so that we can
+    # output the canonical list of all glibc from current_glibc
+    # down to too_old_glibc2, including all intermediary versions.
+    for glibc_major in range(current_glibc.major - 1, 1, -1):
+        glibc_minor = _LAST_GLIBC_MINOR[glibc_major]
+        glibc_max_list.append(_GLibCVersion(glibc_major, glibc_minor))
+    for glibc_max in glibc_max_list:
+        if glibc_max.major == too_old_glibc2.major:
+            min_minor = too_old_glibc2.minor
+        else:
+            # For other glibc major versions oldest supported is (x, 0).
+            min_minor = -1
+        for glibc_minor in range(glibc_max.minor, min_minor, -1):
+            glibc_version = _GLibCVersion(glibc_max.major, glibc_minor)
+            tag = "manylinux_{}_{}".format(*glibc_version)
+            if _is_compatible(tag, arch, glibc_version):
+                yield linux.replace("linux", tag)
+            # Handle the legacy manylinux1, manylinux2010, manylinux2014 tags.
+            if glibc_version in _LEGACY_MANYLINUX_MAP:
+                legacy_tag = _LEGACY_MANYLINUX_MAP[glibc_version]
+                if _is_compatible(legacy_tag, arch, glibc_version):
+                    yield linux.replace("linux", legacy_tag)
diff --git a/third_party/python/setuptools/pkg_resources/_vendor/packaging/_musllinux.py b/third_party/python/setuptools/pkg_resources/_vendor/packaging/_musllinux.py
new file mode 100644
index 0000000000..706ba600a9
--- /dev/null
+++ b/third_party/python/setuptools/pkg_resources/_vendor/packaging/_musllinux.py
@@ -0,0 +1,80 @@
+"""PEP 656 support.
+
+This module implements logic to detect if the currently running Python is
+linked against musl, and what musl version is used.
+"""
+
+import functools
+import re
+import subprocess
+import sys
+from typing import Iterator, NamedTuple, Optional
+
+from ._elffile import ELFFile
+
+
+class _MuslVersion(NamedTuple):
+    major: int
+    minor: int
+
+
+def _parse_musl_version(output: str) -> Optional[_MuslVersion]:
+    lines = [n for n in (n.strip() for n in output.splitlines()) if n]
+    if len(lines) < 2 or lines[0][:4] != "musl":
+        return None
+    m = re.match(r"Version (\d+)\.(\d+)", lines[1])
+    if not m:
+        return None
+    return _MuslVersion(major=int(m.group(1)), minor=int(m.group(2)))
+
+
+@functools.lru_cache()
+def _get_musl_version(executable: str) -> Optional[_MuslVersion]:
+    """Detect currently-running musl runtime version.
+
+    This is done by checking the specified executable's dynamic linking
+    information, and invoking the loader to parse its output for a version
+    string. If the loader is musl, the output would be something like::
+
+        musl libc (x86_64)
+        Version 1.2.2
+        Dynamic Program Loader
+    """
+    try:
+        with open(executable, "rb") as f:
+            ld = ELFFile(f).interpreter
+    except (OSError, TypeError, ValueError):
+        return None
+    if ld is None or "musl" not in ld:
+        return None
+    proc = subprocess.run([ld], stderr=subprocess.PIPE, universal_newlines=True)
+    return _parse_musl_version(proc.stderr)
+
+
+def platform_tags(arch: str) -> Iterator[str]:
+    """Generate musllinux tags compatible to the current platform.
+
+    :param arch: Should be the part of platform tag after the ``linux_``
+        prefix, e.g. ``x86_64``. The ``linux_`` prefix is assumed as a
+        prerequisite for the current platform to be musllinux-compatible.
+
+    :returns: An iterator of compatible musllinux tags.
+    """
+    sys_musl = _get_musl_version(sys.executable)
+    if sys_musl is None:  # Python not dynamically linked against musl.
+        return
+    for minor in range(sys_musl.minor, -1, -1):
+        yield f"musllinux_{sys_musl.major}_{minor}_{arch}"
+
+
+if __name__ == "__main__":  # pragma: no cover
+    import sysconfig
+
+    plat = sysconfig.get_platform()
+    assert plat.startswith("linux-"), "not linux"
+
+    print("plat:", plat)
+    print("musl:", _get_musl_version(sys.executable))
+    print("tags:", end=" ")
+    for t in platform_tags(re.sub(r"[.-]", "_", plat.split("-", 1)[-1])):
+        print(t, end="\n      ")
diff --git a/third_party/python/setuptools/pkg_resources/_vendor/packaging/_parser.py b/third_party/python/setuptools/pkg_resources/_vendor/packaging/_parser.py
new file mode 100644
index 0000000000..5a18b758fe
--- /dev/null
+++ b/third_party/python/setuptools/pkg_resources/_vendor/packaging/_parser.py
@@ -0,0 +1,353 @@
+"""Handwritten parser of dependency specifiers.
+
+The docstring for each __parse_* function contains ENBF-inspired grammar representing
+the implementation.
+"""
+
+import ast
+from typing import Any, List, NamedTuple, Optional, Tuple, Union
+
+from ._tokenizer import DEFAULT_RULES, Tokenizer
+
+
+class Node:
+    def __init__(self, value: str) -> None:
+        self.value = value
+
+    def __str__(self) -> str:
+        return self.value
+
+    def __repr__(self) -> str:
+        return f"<{self.__class__.__name__}('{self}')>"
+
+    def serialize(self) -> str:
+        raise NotImplementedError
+
+
+class Variable(Node):
+    def serialize(self) -> str:
+        return str(self)
+
+
+class Value(Node):
+    def serialize(self) -> str:
+        return f'"{self}"'
+
+
+class Op(Node):
+    def serialize(self) -> str:
+        return str(self)
+
+
+MarkerVar = Union[Variable, Value]
+MarkerItem = Tuple[MarkerVar, Op, MarkerVar]
+# MarkerAtom = Union[MarkerItem, List["MarkerAtom"]]
+# MarkerList = List[Union["MarkerList", MarkerAtom, str]]
+# mypy does not support recursive type definition
+# https://github.com/python/mypy/issues/731
+MarkerAtom = Any
+MarkerList = List[Any]
+
+
+class ParsedRequirement(NamedTuple):
+    name: str
+    url: str
+    extras: List[str]
+    specifier: str
+    marker: Optional[MarkerList]
+
+
+# --------------------------------------------------------------------------------------
+# Recursive descent parser for dependency specifier
+# --------------------------------------------------------------------------------------
+def parse_requirement(source: str) -> ParsedRequirement:
+    return _parse_requirement(Tokenizer(source, rules=DEFAULT_RULES))
+
+
+def _parse_requirement(tokenizer: Tokenizer) -> ParsedRequirement:
+    """
+    requirement = WS? IDENTIFIER WS? extras WS? requirement_details
+    """
+    tokenizer.consume("WS")
+
+    name_token = tokenizer.expect(
+        "IDENTIFIER", expected="package name at the start of dependency specifier"
+    )
+    name = name_token.text
+    tokenizer.consume("WS")
+
+    extras = _parse_extras(tokenizer)
+    tokenizer.consume("WS")
+
+    url, specifier, marker = _parse_requirement_details(tokenizer)
+    tokenizer.expect("END", expected="end of dependency specifier")
+
+    return ParsedRequirement(name, url, extras, specifier, marker)
+
+
+def _parse_requirement_details(
+    tokenizer: Tokenizer,
+) -> Tuple[str, str, Optional[MarkerList]]:
+    """
+    requirement_details = AT URL (WS requirement_marker?)?
+                        | specifier WS? (requirement_marker)?
+    """
+
+    specifier = ""
+    url = ""
+    marker = None
+
+    if tokenizer.check("AT"):
+        tokenizer.read()
+        tokenizer.consume("WS")
+
+        url_start = tokenizer.position
+        url = tokenizer.expect("URL", expected="URL after @").text
+        if tokenizer.check("END", peek=True):
+            return (url, specifier, marker)
+
+        tokenizer.expect("WS", expected="whitespace after URL")
+
+        # The input might end after whitespace.
+        if tokenizer.check("END", peek=True):
+            return (url, specifier, marker)
+
+        marker = _parse_requirement_marker(
+            tokenizer, span_start=url_start, after="URL and whitespace"
+        )
+    else:
+        specifier_start = tokenizer.position
+        specifier = _parse_specifier(tokenizer)
+        tokenizer.consume("WS")
+
+        if tokenizer.check("END", peek=True):
+            return (url, specifier, marker)
+
+        marker = _parse_requirement_marker(
+            tokenizer,
+            span_start=specifier_start,
+            after=(
+                "version specifier"
+                if specifier
+                else "name and no valid version specifier"
+            ),
+        )
+
+    return (url, specifier, marker)
+
+
+def _parse_requirement_marker(
+    tokenizer: Tokenizer, *, span_start: int, after: str
+) -> MarkerList:
+    """
+    requirement_marker = SEMICOLON marker WS?
+    """
+
+    if not tokenizer.check("SEMICOLON"):
+        tokenizer.raise_syntax_error(
+            f"Expected end or semicolon (after {after})",
+            span_start=span_start,
+        )
+    tokenizer.read()
+
+    marker = _parse_marker(tokenizer)
+    tokenizer.consume("WS")
+
+    return marker
+
+
+def _parse_extras(tokenizer: Tokenizer) -> List[str]:
+    """
+    extras = (LEFT_BRACKET wsp* extras_list? wsp* RIGHT_BRACKET)?
+    """
+    if not tokenizer.check("LEFT_BRACKET", peek=True):
+        return []
+
+    with tokenizer.enclosing_tokens(
+        "LEFT_BRACKET",
+        "RIGHT_BRACKET",
+        around="extras",
+    ):
+        tokenizer.consume("WS")
+        extras = _parse_extras_list(tokenizer)
+        tokenizer.consume("WS")
+
+    return extras
+
+
+def _parse_extras_list(tokenizer: Tokenizer) -> List[str]:
+    """
+    extras_list = identifier (wsp* ',' wsp* identifier)*
+    """
+    extras: List[str] = []
+
+    if not tokenizer.check("IDENTIFIER"):
+        return extras
+
+    extras.append(tokenizer.read().text)
+
+    while True:
+        tokenizer.consume("WS")
+        if tokenizer.check("IDENTIFIER", peek=True):
+            tokenizer.raise_syntax_error("Expected comma between extra names")
+        elif not tokenizer.check("COMMA"):
+            break
+
+        tokenizer.read()
+        tokenizer.consume("WS")
+
+        extra_token = tokenizer.expect("IDENTIFIER", expected="extra name after comma")
+        extras.append(extra_token.text)
+
+    return extras
+
+
+def _parse_specifier(tokenizer: Tokenizer) -> str:
+    """
+    specifier = LEFT_PARENTHESIS WS? version_many WS? RIGHT_PARENTHESIS
+              | WS? version_many WS?
+    """
+    with tokenizer.enclosing_tokens(
+        "LEFT_PARENTHESIS",
+        "RIGHT_PARENTHESIS",
+        around="version specifier",
+    ):
+        tokenizer.consume("WS")
+        parsed_specifiers = _parse_version_many(tokenizer)
+        tokenizer.consume("WS")
+
+    return parsed_specifiers
+
+
+def _parse_version_many(tokenizer: Tokenizer) -> str:
+    """
+    version_many = (SPECIFIER (WS? COMMA WS? SPECIFIER)*)?
+    """
+    parsed_specifiers = ""
+    while tokenizer.check("SPECIFIER"):
+        span_start = tokenizer.position
+        parsed_specifiers += tokenizer.read().text
+        if tokenizer.check("VERSION_PREFIX_TRAIL", peek=True):
+            tokenizer.raise_syntax_error(
+                ".* suffix can only be used with `==` or `!=` operators",
+                span_start=span_start,
+                span_end=tokenizer.position + 1,
+            )
+        if tokenizer.check("VERSION_LOCAL_LABEL_TRAIL", peek=True):
+            tokenizer.raise_syntax_error(
+                "Local version label can only be used with `==` or `!=` operators",
+                span_start=span_start,
+                span_end=tokenizer.position,
+            )
+        tokenizer.consume("WS")
+        if not tokenizer.check("COMMA"):
+            break
+        parsed_specifiers += tokenizer.read().text
+        tokenizer.consume("WS")
+
+    return parsed_specifiers
+
+
+# --------------------------------------------------------------------------------------
+# Recursive descent parser for marker expression
+# --------------------------------------------------------------------------------------
+def parse_marker(source: str) -> MarkerList:
+    return _parse_marker(Tokenizer(source, rules=DEFAULT_RULES))
+
+
+def _parse_marker(tokenizer: Tokenizer) -> MarkerList:
+    """
+    marker = marker_atom (BOOLOP marker_atom)+
+    """
+    expression = [_parse_marker_atom(tokenizer)]
+    while tokenizer.check("BOOLOP"):
+        token = tokenizer.read()
+        expr_right = _parse_marker_atom(tokenizer)
+        expression.extend((token.text, expr_right))
+    return expression
+
+
+def _parse_marker_atom(tokenizer: Tokenizer) -> MarkerAtom:
+    """
+    marker_atom = WS? LEFT_PARENTHESIS WS? marker WS? RIGHT_PARENTHESIS WS?
+                | WS? marker_item WS?
+    """
+
+    tokenizer.consume("WS")
+    if tokenizer.check("LEFT_PARENTHESIS", peek=True):
+        with tokenizer.enclosing_tokens(
+            "LEFT_PARENTHESIS",
+            "RIGHT_PARENTHESIS",
+            around="marker expression",
+        ):
+            tokenizer.consume("WS")
+            marker: MarkerAtom = _parse_marker(tokenizer)
+            tokenizer.consume("WS")
+    else:
+        marker = _parse_marker_item(tokenizer)
+    tokenizer.consume("WS")
+    return marker
+
+
+def _parse_marker_item(tokenizer: Tokenizer) -> MarkerItem:
+    """
+    marker_item = WS? marker_var WS? marker_op WS? marker_var WS?
+    """
+    tokenizer.consume("WS")
+    marker_var_left = _parse_marker_var(tokenizer)
+    tokenizer.consume("WS")
+    marker_op = _parse_marker_op(tokenizer)
+    tokenizer.consume("WS")
+    marker_var_right = _parse_marker_var(tokenizer)
+    tokenizer.consume("WS")
+    return (marker_var_left, marker_op, marker_var_right)
+
+
+def _parse_marker_var(tokenizer: Tokenizer) -> MarkerVar:
+    """
+    marker_var = VARIABLE | QUOTED_STRING
+    """
+    if tokenizer.check("VARIABLE"):
+        return process_env_var(tokenizer.read().text.replace(".", "_"))
+    elif tokenizer.check("QUOTED_STRING"):
+        return process_python_str(tokenizer.read().text)
+    else:
+        tokenizer.raise_syntax_error(
+            message="Expected a marker variable or quoted string"
+        )
+
+
+def process_env_var(env_var: str) -> Variable:
+    if (
+        env_var == "platform_python_implementation"
+        or env_var == "python_implementation"
+    ):
+        return Variable("platform_python_implementation")
+    else:
+        return Variable(env_var)
+
+
+def process_python_str(python_str: str) -> Value:
+    value = ast.literal_eval(python_str)
+    return Value(str(value))
+
+
+def _parse_marker_op(tokenizer: Tokenizer) -> Op:
+    """
+    marker_op = IN | NOT IN | OP
+    """
+    if tokenizer.check("IN"):
+        tokenizer.read()
+        return Op("in")
+    elif tokenizer.check("NOT"):
+        tokenizer.read()
+        tokenizer.expect("WS", expected="whitespace after 'not'")
+        tokenizer.expect("IN", expected="'in' after 'not'")
+        return Op("not in")
+    elif tokenizer.check("OP"):
+        return Op(tokenizer.read().text)
+    else:
+        return tokenizer.raise_syntax_error(
+            "Expected marker operator, one of "
+            "<=, <, !=, ==, >=, >, ~=, ===, in, not in"
+        )
diff --git a/third_party/python/setuptools/pkg_resources/_vendor/packaging/_structures.py b/third_party/python/setuptools/pkg_resources/_vendor/packaging/_structures.py
new file mode 100644
index 0000000000..90a6465f96
--- /dev/null
+++ b/third_party/python/setuptools/pkg_resources/_vendor/packaging/_structures.py
@@ -0,0 +1,61 @@
+# This file is dual licensed under the terms of the Apache License, Version
+# 2.0, and the BSD License. See the LICENSE file in the root of this repository
+# for complete details.
+
+
+class InfinityType:
+    def __repr__(self) -> str:
+        return "Infinity"
+
+    def __hash__(self) -> int:
+        return hash(repr(self))
+
+    def __lt__(self, other: object) -> bool:
+        return False
+
+    def __le__(self, other: object) -> bool:
+        return False
+
+    def __eq__(self, other: object) -> bool:
+        return isinstance(other, self.__class__)
+
+    def __gt__(self, other: object) -> bool:
+        return True
+
+    def __ge__(self, other: object) -> bool:
+        return True
+
+    def __neg__(self: object) -> "NegativeInfinityType":
+        return NegativeInfinity
+
+
+Infinity = InfinityType()
+
+
+class NegativeInfinityType:
+    def __repr__(self) -> str:
+        return "-Infinity"
+
+    def __hash__(self) -> int:
+        return hash(repr(self))
+
+    def __lt__(self, other: object) -> bool:
+        return True
+
+    def __le__(self, other: object) -> bool:
+        return True
+
+    def __eq__(self, other: object) -> bool:
+        return isinstance(other, self.__class__)
+
+    def __gt__(self, other: object) -> bool:
+        return False
+
+    def __ge__(self, other: object) -> bool:
+        return False
+
+    def __neg__(self: object) -> InfinityType:
+        return Infinity
+
+
+NegativeInfinity = NegativeInfinityType()
diff --git a/third_party/python/setuptools/pkg_resources/_vendor/packaging/_tokenizer.py b/third_party/python/setuptools/pkg_resources/_vendor/packaging/_tokenizer.py
new file mode 100644
index 0000000000..dd0d648d49
--- /dev/null
+++ b/third_party/python/setuptools/pkg_resources/_vendor/packaging/_tokenizer.py
@@ -0,0 +1,192 @@
+import contextlib
+import re
+from dataclasses import dataclass
+from typing import Dict, Iterator, NoReturn, Optional, Tuple, Union
+
+from .specifiers import Specifier
+
+
+@dataclass
+class Token:
+    name: str
+    text: str
+    position: int
+
+
+class ParserSyntaxError(Exception):
+    """The provided source text could not be parsed correctly."""
+
+    def __init__(
+        self,
+        message: str,
+        *,
+        source: str,
+        span: Tuple[int, int],
+    ) -> None:
+        self.span = span
+        self.message = message
+        self.source = source
+
+        super().__init__()
+
+    def __str__(self) -> str:
+        marker = " " * self.span[0] + "~" * (self.span[1] - self.span[0]) + "^"
+        return "\n    ".join([self.message, self.source, marker])
+
+
+DEFAULT_RULES: "Dict[str, Union[str, re.Pattern[str]]]" = {
+    "LEFT_PARENTHESIS": r"\(",
+    "RIGHT_PARENTHESIS": r"\)",
+    "LEFT_BRACKET": r"\[",
+    "RIGHT_BRACKET": r"\]",
+    "SEMICOLON": r";",
+    "COMMA": r",",
+    "QUOTED_STRING": re.compile(
+        r"""
+            (
+                ('[^']*')
+                |
+                ("[^"]*")
+            )
+        """,
+        re.VERBOSE,
+    ),
+    "OP": r"(===|==|~=|!=|<=|>=|<|>)",
+    "BOOLOP": r"\b(or|and)\b",
+    "IN": r"\bin\b",
+    "NOT": r"\bnot\b",
+    "VARIABLE": re.compile(
+        r"""
+            \b(
+                python_version
+                |python_full_version
+                |os[._]name
+                |sys[._]platform
+                |platform_(release|system)
+                |platform[._](version|machine|python_implementation)
+                |python_implementation
+                |implementation_(name|version)
+                |extra
+            )\b
+        """,
+        re.VERBOSE,
+    ),
+    "SPECIFIER": re.compile(
+        Specifier._operator_regex_str + Specifier._version_regex_str,
+        re.VERBOSE | re.IGNORECASE,
+    ),
+    "AT": r"\@",
+    "URL": r"[^ \t]+",
+    "IDENTIFIER": r"\b[a-zA-Z0-9][a-zA-Z0-9._-]*\b",
+    "VERSION_PREFIX_TRAIL": r"\.\*",
+    "VERSION_LOCAL_LABEL_TRAIL": r"\+[a-z0-9]+(?:[-_\.][a-z0-9]+)*",
+    "WS": r"[ \t]+",
+    "END": r"$",
+}
+
+
+class Tokenizer:
+    """Context-sensitive token parsing.
+
+    Provides methods to examine the input stream to check whether the next token
+    matches.
+    """
+
+    def __init__(
+        self,
+        source: str,
+        *,
+        rules: "Dict[str, Union[str, re.Pattern[str]]]",
+    ) -> None:
+        self.source = source
+        self.rules: Dict[str, re.Pattern[str]] = {
+            name: re.compile(pattern) for name, pattern in rules.items()
+        }
+        self.next_token: Optional[Token] = None
+        self.position = 0
+
+    def consume(self, name: str) -> None:
+        """Move beyond provided token name, if at current position."""
+        if self.check(name):
+            self.read()
+
+    def check(self, name: str, *, peek: bool = False) -> bool:
+        """Check whether the next token has the provided name.
+
+        By default, if the check succeeds, the token *must* be read before
+        another check. If `peek` is set to `True`, the token is not loaded and
+        would need to be checked again.
+        """
+        assert (
+            self.next_token is None
+        ), f"Cannot check for {name!r}, already have {self.next_token!r}"
+        assert name in self.rules, f"Unknown token name: {name!r}"
+
+        expression = self.rules[name]
+
+        match = expression.match(self.source, self.position)
+        if match is None:
+            return False
+        if not peek:
+            self.next_token = Token(name, match[0], self.position)
+        return True
+
+    def expect(self, name: str, *, expected: str) -> Token:
+        """Expect a certain token name next, failing with a syntax error otherwise.
+
+        The token is *not* read.
+        """
+        if not self.check(name):
+            raise self.raise_syntax_error(f"Expected {expected}")
+        return self.read()
+
+    def read(self) -> Token:
+        """Consume the next token and return it."""
+        token = self.next_token
+        assert token is not None
+
+        self.position += len(token.text)
+        self.next_token = None
+
+        return token
+
+    def raise_syntax_error(
+        self,
+        message: str,
+        *,
+        span_start: Optional[int] = None,
+        span_end: Optional[int] = None,
+    ) -> NoReturn:
+        """Raise ParserSyntaxError at the given position."""
+        span = (
+            self.position if span_start is None else span_start,
+            self.position if span_end is None else span_end,
+        )
+        raise ParserSyntaxError(
+            message,
+            source=self.source,
+            span=span,
+        )
+
+    @contextlib.contextmanager
+    def enclosing_tokens(
+        self, open_token: str, close_token: str, *, around: str
+    ) -> Iterator[None]:
+        if self.check(open_token):
+            open_position = self.position
+            self.read()
+        else:
+            open_position = None
+
+        yield
+
+        if open_position is None:
+            return
+
+        if not self.check(close_token):
+            self.raise_syntax_error(
+                f"Expected matching {close_token} for {open_token}, after {around}",
+                span_start=open_position,
+            )
+
+        self.read()
diff --git a/third_party/python/setuptools/pkg_resources/_vendor/packaging/markers.py b/third_party/python/setuptools/pkg_resources/_vendor/packaging/markers.py
new file mode 100644
index 0000000000..8b98fca723
--- /dev/null
+++ b/third_party/python/setuptools/pkg_resources/_vendor/packaging/markers.py
@@ -0,0 +1,252 @@
+# This file is dual licensed under the terms of the Apache License, Version
+# 2.0, and the BSD License. See the LICENSE file in the root of this repository
+# for complete details.
+
+import operator
+import os
+import platform
+import sys
+from typing import Any, Callable, Dict, List, Optional, Tuple, Union
+
+from ._parser import (
+    MarkerAtom,
+    MarkerList,
+    Op,
+    Value,
+    Variable,
+    parse_marker as _parse_marker,
+)
+from ._tokenizer import ParserSyntaxError
+from .specifiers import InvalidSpecifier, Specifier
+from .utils import canonicalize_name
+
+__all__ = [
+    "InvalidMarker",
+    "UndefinedComparison",
+    "UndefinedEnvironmentName",
+    "Marker",
+    "default_environment",
+]
+
+Operator = Callable[[str, str], bool]
+
+
+class InvalidMarker(ValueError):
+    """
+    An invalid marker was found, users should refer to PEP 508.
+    """
+
+
+class UndefinedComparison(ValueError):
+    """
+    An invalid operation was attempted on a value that doesn't support it.
+    """
+
+
+class UndefinedEnvironmentName(ValueError):
+    """
+    A name was attempted to be used that does not exist inside of the
+    environment.
+    """
+
+
+def _normalize_extra_values(results: Any) -> Any:
+    """
+    Normalize extra values.
+    """
+    if isinstance(results[0], tuple):
+        lhs, op, rhs = results[0]
+        if isinstance(lhs, Variable) and lhs.value == "extra":
+            normalized_extra = canonicalize_name(rhs.value)
+            rhs = Value(normalized_extra)
+        elif isinstance(rhs, Variable) and rhs.value == "extra":
+            normalized_extra = canonicalize_name(lhs.value)
+            lhs = Value(normalized_extra)
+        results[0] = lhs, op, rhs
+    return results
+
+
+def _format_marker(
+    marker: Union[List[str], MarkerAtom, str], first: Optional[bool] = True
+) -> str:
+
+    assert isinstance(marker, (list, tuple, str))
+
+    # Sometimes we have a structure like [[...]] which is a single item list
+    # where the single item is itself it's own list. In that case we want skip
+    # the rest of this function so that we don't get extraneous () on the
+    # outside.
+    if (
+        isinstance(marker, list)
+        and len(marker) == 1
+        and isinstance(marker[0], (list, tuple))
+    ):
+        return _format_marker(marker[0])
+
+    if isinstance(marker, list):
+        inner = (_format_marker(m, first=False) for m in marker)
+        if first:
+            return " ".join(inner)
+        else:
+            return "(" + " ".join(inner) + ")"
+    elif isinstance(marker, tuple):
+        return " ".join([m.serialize() for m in marker])
+    else:
+        return marker
+
+
+_operators: Dict[str, Operator] = {
+    "in": lambda lhs, rhs: lhs in rhs,
+    "not in": lambda lhs, rhs: lhs not in rhs,
+    "<": operator.lt,
+    "<=": operator.le,
+    "==": operator.eq,
+    "!=": operator.ne,
+    ">=": operator.ge,
+    ">": operator.gt,
+}
+
+
+def _eval_op(lhs: str, op: Op, rhs: str) -> bool:
+    try:
+        spec = Specifier("".join([op.serialize(), rhs]))
+    except InvalidSpecifier:
+        pass
+    else:
+        return spec.contains(lhs, prereleases=True)
+
+    oper: Optional[Operator] = _operators.get(op.serialize())
+    if oper is None:
+        raise UndefinedComparison(f"Undefined {op!r} on {lhs!r} and {rhs!r}.")
+
+    return oper(lhs, rhs)
+
+
+def _normalize(*values: str, key: str) -> Tuple[str, ...]:
+    # PEP 685 – Comparison of extra names for optional distribution dependencies
+    # https://peps.python.org/pep-0685/
+    # > When comparing extra names, tools MUST normalize the names being
+    # > compared using the semantics outlined in PEP 503 for names
+    if key == "extra":
+        return tuple(canonicalize_name(v) for v in values)
+
+    # other environment markers don't have such standards
+    return values
+
+
+def _evaluate_markers(markers: MarkerList, environment: Dict[str, str]) -> bool:
+    groups: List[List[bool]] = [[]]
+
+    for marker in markers:
+        assert isinstance(marker, (list, tuple, str))
+
+        if isinstance(marker, list):
+            groups[-1].append(_evaluate_markers(marker, environment))
+        elif isinstance(marker, tuple):
+            lhs, op, rhs = marker
+
+            if isinstance(lhs, Variable):
+                environment_key = lhs.value
+                lhs_value = environment[environment_key]
+                rhs_value = rhs.value
+            else:
+                lhs_value = lhs.value
+                environment_key = rhs.value
+                rhs_value = environment[environment_key]
+
+            lhs_value, rhs_value = _normalize(lhs_value, rhs_value, key=environment_key)
+            groups[-1].append(_eval_op(lhs_value, op, rhs_value))
+        else:
+            assert marker in ["and", "or"]
+            if marker == "or":
+                groups.append([])
+
+    return any(all(item) for item in groups)
+
+
+def format_full_version(info: "sys._version_info") -> str:
+    version = "{0.major}.{0.minor}.{0.micro}".format(info)
+    kind = info.releaselevel
+    if kind != "final":
+        version += kind[0] + str(info.serial)
+    return version
+
+
+def default_environment() -> Dict[str, str]:
+    iver = format_full_version(sys.implementation.version)
+    implementation_name = sys.implementation.name
+    return {
+        "implementation_name": implementation_name,
+        "implementation_version": iver,
+        "os_name": os.name,
+        "platform_machine": platform.machine(),
+        "platform_release": platform.release(),
+        "platform_system": platform.system(),
+        "platform_version": platform.version(),
+        "python_full_version": platform.python_version(),
+        "platform_python_implementation": platform.python_implementation(),
+        "python_version": ".".join(platform.python_version_tuple()[:2]),
+        "sys_platform": sys.platform,
+    }
+
+
+class Marker:
+    def __init__(self, marker: str) -> None:
+        # Note: We create a Marker object without calling this constructor in
+        #       packaging.requirements.Requirement. If any additional logic is
+        #       added here, make sure to mirror/adapt Requirement.
+        try:
+            self._markers = _normalize_extra_values(_parse_marker(marker))
+            # The attribute `_markers` can be described in terms of a recursive type:
+            # MarkerList = List[Union[Tuple[Node, ...], str, MarkerList]]
+            #
+            # For example, the following expression:
+            # python_version > "3.6" or (python_version == "3.6" and os_name == "unix")
+            #
+            # is parsed into:
+            # [
+            #     (<Variable('python_version')>, <Op('>')>, <Value('3.6')>),
+            #     'and',
+            #     [
+            #         (<Variable('python_version')>, <Op('==')>, <Value('3.6')>),
+            #         'or',
+            #         (<Variable('os_name')>, <Op('==')>, <Value('unix')>)
+            #     ]
+            # ]
+        except ParserSyntaxError as e:
+            raise InvalidMarker(str(e)) from e
+
+    def __str__(self) -> str:
+        return _format_marker(self._markers)
+
+    def __repr__(self) -> str:
+        return f"<Marker('{self}')>"
+
+    def __hash__(self) -> int:
+        return hash((self.__class__.__name__, str(self)))
+
+    def __eq__(self, other: Any) -> bool:
+        if not isinstance(other, Marker):
+            return NotImplemented
+
+        return str(self) == str(other)
+
+    def evaluate(self, environment: Optional[Dict[str, str]] = None) -> bool:
+        """Evaluate a marker.
+
+        Return the boolean from evaluating the given marker against the
+        environment. environment is an optional argument to override all or
+        part of the determined environment.
+
+        The environment is determined from the current Python process.
+        """
+        current_environment = default_environment()
+        current_environment["extra"] = ""
+        if environment is not None:
+            current_environment.update(environment)
+            # The API used to allow setting extra to None. We need to handle this
+            # case for backwards compatibility.
+            if current_environment["extra"] is None:
+                current_environment["extra"] = ""
+
+        return _evaluate_markers(self._markers, current_environment)
diff --git a/third_party/python/setuptools/pkg_resources/_vendor/packaging/metadata.py b/third_party/python/setuptools/pkg_resources/_vendor/packaging/metadata.py
new file mode 100644
index 0000000000..e76a60c395
--- /dev/null
+++ b/third_party/python/setuptools/pkg_resources/_vendor/packaging/metadata.py
@@ -0,0 +1,408 @@
+import email.feedparser
+import email.header
+import email.message
+import email.parser
+import email.policy
+import sys
+import typing
+from typing import Dict, List, Optional, Tuple, Union, cast
+
+if sys.version_info >= (3, 8):  # pragma: no cover
+    from typing import TypedDict
+else:  # pragma: no cover
+    if typing.TYPE_CHECKING:
+        from typing_extensions import TypedDict
+    else:
+        try:
+            from typing_extensions import TypedDict
+        except ImportError:
+
+            class TypedDict:
+                def __init_subclass__(*_args, **_kwargs):
+                    pass
+
+
+# The RawMetadata class attempts to make as few assumptions about the underlying
+# serialization formats as possible. The idea is that as long as a serialization
+# formats offer some very basic primitives in *some* way then we can support
+# serializing to and from that format.
+class RawMetadata(TypedDict, total=False):
+    """A dictionary of raw core metadata.
+
+    Each field in core metadata maps to a key of this dictionary (when data is
+    provided). The key is lower-case and underscores are used instead of dashes
+    compared to the equivalent core metadata field. Any core metadata field that
+    can be specified multiple times or can hold multiple values in a single
+    field have a key with a plural name.
+
+    Core metadata fields that can be specified multiple times are stored as a
+    list or dict depending on which is appropriate for the field. Any fields
+    which hold multiple values in a single field are stored as a list.
+
+    """
+
+    # Metadata 1.0 - PEP 241
+    metadata_version: str
+    name: str
+    version: str
+    platforms: List[str]
+    summary: str
+    description: str
+    keywords: List[str]
+    home_page: str
+    author: str
+    author_email: str
+    license: str
+
+    # Metadata 1.1 - PEP 314
+    supported_platforms: List[str]
+    download_url: str
+    classifiers: List[str]
+    requires: List[str]
+    provides: List[str]
+    obsoletes: List[str]
+
+    # Metadata 1.2 - PEP 345
+    maintainer: str
+    maintainer_email: str
+    requires_dist: List[str]
+    provides_dist: List[str]
+    obsoletes_dist: List[str]
+    requires_python: str
+    requires_external: List[str]
+    project_urls: Dict[str, str]
+
+    # Metadata 2.0
+    # PEP 426 attempted to completely revamp the metadata format
+    # but got stuck without ever being able to build consensus on
+    # it and ultimately ended up withdrawn.
+    #
+    # However, a number of tools had started emiting METADATA with
+    # `2.0` Metadata-Version, so for historical reasons, this version
+    # was skipped.
+
+    # Metadata 2.1 - PEP 566
+    description_content_type: str
+    provides_extra: List[str]
+
+    # Metadata 2.2 - PEP 643
+    dynamic: List[str]
+
+    # Metadata 2.3 - PEP 685
+    # No new fields were added in PEP 685, just some edge case were
+    # tightened up to provide better interoptability.
+
+
+_STRING_FIELDS = {
+    "author",
+    "author_email",
+    "description",
+    "description_content_type",
+    "download_url",
+    "home_page",
+    "license",
+    "maintainer",
+    "maintainer_email",
+    "metadata_version",
+    "name",
+    "requires_python",
+    "summary",
+    "version",
+}
+
+_LIST_STRING_FIELDS = {
+    "classifiers",
+    "dynamic",
+    "obsoletes",
+    "obsoletes_dist",
+    "platforms",
+    "provides",
+    "provides_dist",
+    "provides_extra",
+    "requires",
+    "requires_dist",
+    "requires_external",
+    "supported_platforms",
+}
+
+
+def _parse_keywords(data: str) -> List[str]:
+    """Split a string of comma-separate keyboards into a list of keywords."""
+    return [k.strip() for k in data.split(",")]
+
+
+def _parse_project_urls(data: List[str]) -> Dict[str, str]:
+    """Parse a list of label/URL string pairings separated by a comma."""
+    urls = {}
+    for pair in data:
+        # Our logic is slightly tricky here as we want to try and do
+        # *something* reasonable with malformed data.
+        #
+        # The main thing that we have to worry about, is data that does
+        # not have a ',' at all to split the label from the Value. There
+        # isn't a singular right answer here, and we will fail validation
+        # later on (if the caller is validating) so it doesn't *really*
+        # matter, but since the missing value has to be an empty str
+        # and our return value is dict[str, str], if we let the key
+        # be the missing value, then they'd have multiple '' values that
+        # overwrite each other in a accumulating dict.
+        #
+        # The other potentional issue is that it's possible to have the
+        # same label multiple times in the metadata, with no solid "right"
+        # answer with what to do in that case. As such, we'll do the only
+        # thing we can, which is treat the field as unparseable and add it
+        # to our list of unparsed fields.
+        parts = [p.strip() for p in pair.split(",", 1)]
+        parts.extend([""] * (max(0, 2 - len(parts))))  # Ensure 2 items
+
+        # TODO: The spec doesn't say anything about if the keys should be
+        #       considered case sensitive or not... logically they should
+        #       be case-preserving and case-insensitive, but doing that
+        #       would open up more cases where we might have duplicate
+        #       entries.
+        label, url = parts
+        if label in urls:
+            # The label already exists in our set of urls, so this field
+            # is unparseable, and we can just add the whole thing to our
+            # unparseable data and stop processing it.
+            raise KeyError("duplicate labels in project urls")
+        urls[label] = url
+
+    return urls
+
+
+def _get_payload(msg: email.message.Message, source: Union[bytes, str]) -> str:
+    """Get the body of the message."""
+    # If our source is a str, then our caller has managed encodings for us,
+    # and we don't need to deal with it.
+    if isinstance(source, str):
+        payload: str = msg.get_payload()
+        return payload
+    # If our source is a bytes, then we're managing the encoding and we need
+    # to deal with it.
+    else:
+        bpayload: bytes = msg.get_payload(decode=True)
+        try:
+            return bpayload.decode("utf8", "strict")
+        except UnicodeDecodeError:
+            raise ValueError("payload in an invalid encoding")
+
+
+# The various parse_FORMAT functions here are intended to be as lenient as
+# possible in their parsing, while still returning a correctly typed
+# RawMetadata.
+#
+# To aid in this, we also generally want to do as little touching of the
+# data as possible, except where there are possibly some historic holdovers
+# that make valid data awkward to work with.
+#
+# While this is a lower level, intermediate format than our ``Metadata``
+# class, some light touch ups can make a massive difference in usability.
+
+# Map METADATA fields to RawMetadata.
+_EMAIL_TO_RAW_MAPPING = {
+    "author": "author",
+    "author-email": "author_email",
+    "classifier": "classifiers",
+    "description": "description",
+    "description-content-type": "description_content_type",
+    "download-url": "download_url",
+    "dynamic": "dynamic",
+    "home-page": "home_page",
+    "keywords": "keywords",
+    "license": "license",
+    "maintainer": "maintainer",
+    "maintainer-email": "maintainer_email",
+    "metadata-version": "metadata_version",
+    "name": "name",
+    "obsoletes": "obsoletes",
+    "obsoletes-dist": "obsoletes_dist",
+    "platform": "platforms",
+    "project-url": "project_urls",
+    "provides": "provides",
+    "provides-dist": "provides_dist",
+    "provides-extra": "provides_extra",
+    "requires": "requires",
+    "requires-dist": "requires_dist",
+    "requires-external": "requires_external",
+    "requires-python": "requires_python",
+    "summary": "summary",
+    "supported-platform": "supported_platforms",
+    "version": "version",
+}
+
+
+def parse_email(data: Union[bytes, str]) -> Tuple[RawMetadata, Dict[str, List[str]]]:
+    """Parse a distribution's metadata.
+
+    This function returns a two-item tuple of dicts. The first dict is of
+    recognized fields from the core metadata specification. Fields that can be
+    parsed and translated into Python's built-in types are converted
+    appropriately. All other fields are left as-is. Fields that are allowed to
+    appear multiple times are stored as lists.
+
+    The second dict contains all other fields from the metadata. This includes
+    any unrecognized fields. It also includes any fields which are expected to
+    be parsed into a built-in type but were not formatted appropriately. Finally,
+    any fields that are expected to appear only once but are repeated are
+    included in this dict.
+
+    """
+    raw: Dict[str, Union[str, List[str], Dict[str, str]]] = {}
+    unparsed: Dict[str, List[str]] = {}
+
+    if isinstance(data, str):
+        parsed = email.parser.Parser(policy=email.policy.compat32).parsestr(data)
+    else:
+        parsed = email.parser.BytesParser(policy=email.policy.compat32).parsebytes(data)
+
+    # We have to wrap parsed.keys() in a set, because in the case of multiple
+    # values for a key (a list), the key will appear multiple times in the
+    # list of keys, but we're avoiding that by using get_all().
+    for name in frozenset(parsed.keys()):
+        # Header names in RFC are case insensitive, so we'll normalize to all
+        # lower case to make comparisons easier.
+        name = name.lower()
+
+        # We use get_all() here, even for fields that aren't multiple use,
+        # because otherwise someone could have e.g. two Name fields, and we
+        # would just silently ignore it rather than doing something about it.
+        headers = parsed.get_all(name)
+
+        # The way the email module works when parsing bytes is that it
+        # unconditionally decodes the bytes as ascii using the surrogateescape
+        # handler. When you pull that data back out (such as with get_all() ),
+        # it looks to see if the str has any surrogate escapes, and if it does
+        # it wraps it in a Header object instead of returning the string.
+        #
+        # As such, we'll look for those Header objects, and fix up the encoding.
+        value = []
+        # Flag if we have run into any issues processing the headers, thus
+        # signalling that the data belongs in 'unparsed'.
+        valid_encoding = True
+        for h in headers:
+            # It's unclear if this can return more types than just a Header or
+            # a str, so we'll just assert here to make sure.
+            assert isinstance(h, (email.header.Header, str))
+
+            # If it's a header object, we need to do our little dance to get
+            # the real data out of it. In cases where there is invalid data
+            # we're going to end up with mojibake, but there's no obvious, good
+            # way around that without reimplementing parts of the Header object
+            # ourselves.
+            #
+            # That should be fine since, if mojibacked happens, this key is
+            # going into the unparsed dict anyways.
+            if isinstance(h, email.header.Header):
+                # The Header object stores it's data as chunks, and each chunk
+                # can be independently encoded, so we'll need to check each
+                # of them.
+                chunks: List[Tuple[bytes, Optional[str]]] = []
+                for bin, encoding in email.header.decode_header(h):
+                    try:
+                        bin.decode("utf8", "strict")
+                    except UnicodeDecodeError:
+                        # Enable mojibake.
+                        encoding = "latin1"
+                        valid_encoding = False
+                    else:
+                        encoding = "utf8"
+                    chunks.append((bin, encoding))
+
+                # Turn our chunks back into a Header object, then let that
+                # Header object do the right thing to turn them into a
+                # string for us.
+                value.append(str(email.header.make_header(chunks)))
+            # This is already a string, so just add it.
+            else:
+                value.append(h)
+
+        # We've processed all of our values to get them into a list of str,
+        # but we may have mojibake data, in which case this is an unparsed
+        # field.
+        if not valid_encoding:
+            unparsed[name] = value
+            continue
+
+        raw_name = _EMAIL_TO_RAW_MAPPING.get(name)
+        if raw_name is None:
+            # This is a bit of a weird situation, we've encountered a key that
+            # we don't know what it means, so we don't know whether it's meant
+            # to be a list or not.
+            #
+            # Since we can't really tell one way or another, we'll just leave it
+            # as a list, even though it may be a single item list, because that's
+            # what makes the most sense for email headers.
+            unparsed[name] = value
+            continue
+
+        # If this is one of our string fields, then we'll check to see if our
+        # value is a list of a single item. If it is then we'll assume that
+        # it was emitted as a single string, and unwrap the str from inside
+        # the list.
+        #
+        # If it's any other kind of data, then we haven't the faintest clue
+        # what we should parse it as, and we have to just add it to our list
+        # of unparsed stuff.
+        if raw_name in _STRING_FIELDS and len(value) == 1:
+            raw[raw_name] = value[0]
+        # If this is one of our list of string fields, then we can just assign
+        # the value, since email *only* has strings, and our get_all() call
+        # above ensures that this is a list.
+        elif raw_name in _LIST_STRING_FIELDS:
+            raw[raw_name] = value
+        # Special Case: Keywords
+        # The keywords field is implemented in the metadata spec as a str,
+        # but it conceptually is a list of strings, and is serialized using
+        # ", ".join(keywords), so we'll do some light data massaging to turn
+        # this into what it logically is.
+        elif raw_name == "keywords" and len(value) == 1:
+            raw[raw_name] = _parse_keywords(value[0])
+        # Special Case: Project-URL
+        # The project urls is implemented in the metadata spec as a list of
+        # specially-formatted strings that represent a key and a value, which
+        # is fundamentally a mapping, however the email format doesn't support
+        # mappings in a sane way, so it was crammed into a list of strings
+        # instead.
+        #
+        # We will do a little light data massaging to turn this into a map as
+        # it logically should be.
+        elif raw_name == "project_urls":
+            try:
+                raw[raw_name] = _parse_project_urls(value)
+            except KeyError:
+                unparsed[name] = value
+        # Nothing that we've done has managed to parse this, so it'll just
+        # throw it in our unparseable data and move on.
+        else:
+            unparsed[name] = value
+
+    # We need to support getting the Description from the message payload in
+    # addition to getting it from the the headers. This does mean, though, there
+    # is the possibility of it being set both ways, in which case we put both
+    # in 'unparsed' since we don't know which is right.
+    try:
+        payload = _get_payload(parsed, data)
+    except ValueError:
+        unparsed.setdefault("description", []).append(
+            parsed.get_payload(decode=isinstance(data, bytes))
+        )
+    else:
+        if payload:
+            # Check to see if we've already got a description, if so then both
+            # it, and this body move to unparseable.
+            if "description" in raw:
+                description_header = cast(str, raw.pop("description"))
+                unparsed.setdefault("description", []).extend(
+                    [description_header, payload]
+                )
+            elif "description" in unparsed:
+                unparsed["description"].append(payload)
+            else:
+                raw["description"] = payload
+
+    # We need to cast our `raw` to a metadata, because a TypedDict only support
+    # literal key names, but we're computing our key names on purpose, but the
+    # way this function is implemented, our `TypedDict` can only have valid key
+    # names.
+    return cast(RawMetadata, raw), unparsed
diff --git a/third_party/python/setuptools/pkg_resources/_vendor/packaging/requirements.py b/third_party/python/setuptools/pkg_resources/_vendor/packaging/requirements.py
new file mode 100644
index 0000000000..f34bfa85c8
--- /dev/null
+++ b/third_party/python/setuptools/pkg_resources/_vendor/packaging/requirements.py
@@ -0,0 +1,95 @@
+# This file is dual licensed under the terms of the Apache License, Version
+# 2.0, and the BSD License. See the LICENSE file in the root of this repository
+# for complete details.
+
+import urllib.parse
+from typing import Any, List, Optional, Set
+
+from ._parser import parse_requirement as _parse_requirement
+from ._tokenizer import ParserSyntaxError
+from .markers import Marker, _normalize_extra_values
+from .specifiers import SpecifierSet
+
+
+class InvalidRequirement(ValueError):
+    """
+    An invalid requirement was found, users should refer to PEP 508.
+    """
+
+
+class Requirement:
+    """Parse a requirement.
+
+    Parse a given requirement string into its parts, such as name, specifier,
+    URL, and extras. Raises InvalidRequirement on a badly-formed requirement
+    string.
+    """
+
+    # TODO: Can we test whether something is contained within a requirement?
+    #       If so how do we do that? Do we need to test against the _name_ of
+    #       the thing as well as the version? What about the markers?
+    # TODO: Can we normalize the name and extra name?
+
+    def __init__(self, requirement_string: str) -> None:
+        try:
+            parsed = _parse_requirement(requirement_string)
+        except ParserSyntaxError as e:
+            raise InvalidRequirement(str(e)) from e
+
+        self.name: str = parsed.name
+        if parsed.url:
+            parsed_url = urllib.parse.urlparse(parsed.url)
+            if parsed_url.scheme == "file":
+                if urllib.parse.urlunparse(parsed_url) != parsed.url:
+                    raise InvalidRequirement("Invalid URL given")
+            elif not (parsed_url.scheme and parsed_url.netloc) or (
+                not parsed_url.scheme and not parsed_url.netloc
+            ):
+                raise InvalidRequirement(f"Invalid URL: {parsed.url}")
+            self.url: Optional[str] = parsed.url
+        else:
+            self.url = None
+        self.extras: Set[str] = set(parsed.extras if parsed.extras else [])
+        self.specifier: SpecifierSet = SpecifierSet(parsed.specifier)
+        self.marker: Optional[Marker] = None
+        if parsed.marker is not None:
+            self.marker = Marker.__new__(Marker)
+            self.marker._markers = _normalize_extra_values(parsed.marker)
+
+    def __str__(self) -> str:
+        parts: List[str] = [self.name]
+
+        if self.extras:
+            formatted_extras = ",".join(sorted(self.extras))
+            parts.append(f"[{formatted_extras}]")
+
+        if self.specifier:
+            parts.append(str(self.specifier))
+
+        if self.url:
+            parts.append(f"@ {self.url}")
+            if self.marker:
+                parts.append(" ")
+
+        if self.marker:
+            parts.append(f"; {self.marker}")
+
+        return "".join(parts)
+
+    def __repr__(self) -> str:
+        return f"<Requirement('{self}')>"
+
+    def __hash__(self) -> int:
+        return hash((self.__class__.__name__, str(self)))
+
+    def __eq__(self, other: Any) -> bool:
+        if not isinstance(other, Requirement):
+            return NotImplemented
+
+        return (
+            self.name == other.name
+            and self.extras == other.extras
+            and self.specifier == other.specifier
+            and self.url == other.url
+            and self.marker == other.marker
+        )
diff --git a/third_party/python/setuptools/pkg_resources/_vendor/packaging/specifiers.py b/third_party/python/setuptools/pkg_resources/_vendor/packaging/specifiers.py
new file mode 100644
index 0000000000..ba8fe37b7f
--- /dev/null
+++ b/third_party/python/setuptools/pkg_resources/_vendor/packaging/specifiers.py
@@ -0,0 +1,1008 @@
+# This file is dual licensed under the terms of the Apache License, Version
+# 2.0, and the BSD License. See the LICENSE file in the root of this repository
+# for complete details.
+"""
+.. testsetup::
+
+    from packaging.specifiers import Specifier, SpecifierSet, InvalidSpecifier
+    from packaging.version import Version
+"""
+
+import abc
+import itertools
+import re
+from typing import (
+    Callable,
+    Iterable,
+    Iterator,
+    List,
+    Optional,
+    Set,
+    Tuple,
+    TypeVar,
+    Union,
+)
+
+from .utils import canonicalize_version
+from .version import Version
+
+UnparsedVersion = Union[Version, str]
+UnparsedVersionVar = TypeVar("UnparsedVersionVar", bound=UnparsedVersion)
+CallableOperator = Callable[[Version, str], bool]
+
+
+def _coerce_version(version: UnparsedVersion) -> Version:
+    if not isinstance(version, Version):
+        version = Version(version)
+    return version
+
+
+class InvalidSpecifier(ValueError):
+    """
+    Raised when attempting to create a :class:`Specifier` with a specifier
+    string that is invalid.
+
+    >>> Specifier("lolwat")
+    Traceback (most recent call last):
+        ...
+    packaging.specifiers.InvalidSpecifier: Invalid specifier: 'lolwat'
+    """
+
+
+class BaseSpecifier(metaclass=abc.ABCMeta):
+    @abc.abstractmethod
+    def __str__(self) -> str:
+        """
+        Returns the str representation of this Specifier-like object. This
+        should be representative of the Specifier itself.
+        """
+
+    @abc.abstractmethod
+    def __hash__(self) -> int:
+        """
+        Returns a hash value for this Specifier-like object.
+        """
+
+    @abc.abstractmethod
+    def __eq__(self, other: object) -> bool:
+        """
+        Returns a boolean representing whether or not the two Specifier-like
+        objects are equal.
+
+        :param other: The other object to check against.
+        """
+
+    @property
+    @abc.abstractmethod
+    def prereleases(self) -> Optional[bool]:
+        """Whether or not pre-releases as a whole are allowed.
+
+        This can be set to either ``True`` or ``False`` to explicitly enable or disable
+        prereleases or it can be set to ``None`` (the default) to use default semantics.
+        """
+
+    @prereleases.setter
+    def prereleases(self, value: bool) -> None:
+        """Setter for :attr:`prereleases`.
+
+        :param value: The value to set.
+        """
+
+    @abc.abstractmethod
+    def contains(self, item: str, prereleases: Optional[bool] = None) -> bool:
+        """
+        Determines if the given item is contained within this specifier.
+        """
+
+    @abc.abstractmethod
+    def filter(
+        self, iterable: Iterable[UnparsedVersionVar], prereleases: Optional[bool] = None
+    ) -> Iterator[UnparsedVersionVar]:
+        """
+        Takes an iterable of items and filters them so that only items which
+        are contained within this specifier are allowed in it.
+        """
+
+
+class Specifier(BaseSpecifier):
+    """This class abstracts handling of version specifiers.
+
+    .. tip::
+
+        It is generally not required to instantiate this manually. You should instead
+        prefer to work with :class:`SpecifierSet` instead, which can parse
+        comma-separated version specifiers (which is what package metadata contains).
+    """
+
+    _operator_regex_str = r"""
+        (?P<operator>(~=|==|!=|<=|>=|<|>|===))
+        """
+    _version_regex_str = r"""
+        (?P<version>
+            (?:
+                # The identity operators allow for an escape hatch that will
+                # do an exact string match of the version you wish to install.
+                # This will not be parsed by PEP 440 and we cannot determine
+                # any semantic meaning from it. This operator is discouraged
+                # but included entirely as an escape hatch.
+                (?<====)  # Only match for the identity operator
+                \s*
+                [^\s;)]*  # The arbitrary version can be just about anything,
+                          # we match everything except for whitespace, a
+                          # semi-colon for marker support, and a closing paren
+                          # since versions can be enclosed in them.
+            )
+            |
+            (?:
+                # The (non)equality operators allow for wild card and local
+                # versions to be specified so we have to define these two
+                # operators separately to enable that.
+                (?<===|!=)            # Only match for equals and not equals
+
+                \s*
+                v?
+                (?:[0-9]+!)?          # epoch
+                [0-9]+(?:\.[0-9]+)*   # release
+
+                # You cannot use a wild card and a pre-release, post-release, a dev or
+                # local version together so group them with a | and make them optional.
+                (?:
+                    \.\*  # Wild card syntax of .*
+                    |
+                    (?:                                  # pre release
+                        [-_\.]?
+                        (alpha|beta|preview|pre|a|b|c|rc)
+                        [-_\.]?
+                        [0-9]*
+                    )?
+                    (?:                                  # post release
+                        (?:-[0-9]+)|(?:[-_\.]?(post|rev|r)[-_\.]?[0-9]*)
+                    )?
+                    (?:[-_\.]?dev[-_\.]?[0-9]*)?         # dev release
+                    (?:\+[a-z0-9]+(?:[-_\.][a-z0-9]+)*)? # local
+                )?
+            )
+            |
+            (?:
+                # The compatible operator requires at least two digits in the
+                # release segment.
+                (?<=~=)               # Only match for the compatible operator
+
+                \s*
+                v?
+                (?:[0-9]+!)?          # epoch
+                [0-9]+(?:\.[0-9]+)+   # release  (We have a + instead of a *)
+                (?:                   # pre release
+                    [-_\.]?
+                    (alpha|beta|preview|pre|a|b|c|rc)
+                    [-_\.]?
+                    [0-9]*
+                )?
+                (?:                                   # post release
+                    (?:-[0-9]+)|(?:[-_\.]?(post|rev|r)[-_\.]?[0-9]*)
+                )?
+                (?:[-_\.]?dev[-_\.]?[0-9]*)?          # dev release
+            )
+            |
+            (?:
+                # All other operators only allow a sub set of what the
+                # (non)equality operators do. Specifically they do not allow
+                # local versions to be specified nor do they allow the prefix
+                # matching wild cards.
+                (?<!==|!=|~=)         # We have special cases for these
+                                      # operators so we want to make sure they
+                                      # don't match here.
+
+                \s*
+                v?
+                (?:[0-9]+!)?          # epoch
+                [0-9]+(?:\.[0-9]+)*   # release
+                (?:                   # pre release
+                    [-_\.]?
+                    (alpha|beta|preview|pre|a|b|c|rc)
+                    [-_\.]?
+                    [0-9]*
+                )?
+                (?:                                   # post release
+                    (?:-[0-9]+)|(?:[-_\.]?(post|rev|r)[-_\.]?[0-9]*)
+                )?
+                (?:[-_\.]?dev[-_\.]?[0-9]*)?          # dev release
+            )
+        )
+        """
+
+    _regex = re.compile(
+        r"^\s*" + _operator_regex_str + _version_regex_str + r"\s*$",
+        re.VERBOSE | re.IGNORECASE,
+    )
+
+    _operators = {
+        "~=": "compatible",
+        "==": "equal",
+        "!=": "not_equal",
+        "<=": "less_than_equal",
+        ">=": "greater_than_equal",
+        "<": "less_than",
+        ">": "greater_than",
+        "===": "arbitrary",
+    }
+
+    def __init__(self, spec: str = "", prereleases: Optional[bool] = None) -> None:
+        """Initialize a Specifier instance.
+
+        :param spec:
+            The string representation of a specifier which will be parsed and
+            normalized before use.
+        :param prereleases:
+            This tells the specifier if it should accept prerelease versions if
+            applicable or not. The default of ``None`` will autodetect it from the
+            given specifiers.
+        :raises InvalidSpecifier:
+            If the given specifier is invalid (i.e. bad syntax).
+        """
+        match = self._regex.search(spec)
+        if not match:
+            raise InvalidSpecifier(f"Invalid specifier: '{spec}'")
+
+        self._spec: Tuple[str, str] = (
+            match.group("operator").strip(),
+            match.group("version").strip(),
+        )
+
+        # Store whether or not this Specifier should accept prereleases
+        self._prereleases = prereleases
+
+    # https://github.com/python/mypy/pull/13475#pullrequestreview-1079784515
+    @property  # type: ignore[override]
+    def prereleases(self) -> bool:
+        # If there is an explicit prereleases set for this, then we'll just
+        # blindly use that.
+        if self._prereleases is not None:
+            return self._prereleases
+
+        # Look at all of our specifiers and determine if they are inclusive
+        # operators, and if they are if they are including an explicit
+        # prerelease.
+        operator, version = self._spec
+        if operator in ["==", ">=", "<=", "~=", "==="]:
+            # The == specifier can include a trailing .*, if it does we
+            # want to remove before parsing.
+            if operator == "==" and version.endswith(".*"):
+                version = version[:-2]
+
+            # Parse the version, and if it is a pre-release than this
+            # specifier allows pre-releases.
+            if Version(version).is_prerelease:
+                return True
+
+        return False
+
+    @prereleases.setter
+    def prereleases(self, value: bool) -> None:
+        self._prereleases = value
+
+    @property
+    def operator(self) -> str:
+        """The operator of this specifier.
+
+        >>> Specifier("==1.2.3").operator
+        '=='
+        """
+        return self._spec[0]
+
+    @property
+    def version(self) -> str:
+        """The version of this specifier.
+
+        >>> Specifier("==1.2.3").version
+        '1.2.3'
+        """
+        return self._spec[1]
+
+    def __repr__(self) -> str:
+        """A representation of the Specifier that shows all internal state.
+
+        >>> Specifier('>=1.0.0')
+        <Specifier('>=1.0.0')>
+        >>> Specifier('>=1.0.0', prereleases=False)
+        <Specifier('>=1.0.0', prereleases=False)>
+        >>> Specifier('>=1.0.0', prereleases=True)
+        <Specifier('>=1.0.0', prereleases=True)>
+        """
+        pre = (
+            f", prereleases={self.prereleases!r}"
+            if self._prereleases is not None
+            else ""
+        )
+
+        return f"<{self.__class__.__name__}({str(self)!r}{pre})>"
+
+    def __str__(self) -> str:
+        """A string representation of the Specifier that can be round-tripped.
+
+        >>> str(Specifier('>=1.0.0'))
+        '>=1.0.0'
+        >>> str(Specifier('>=1.0.0', prereleases=False))
+        '>=1.0.0'
+        """
+        return "{}{}".format(*self._spec)
+
+    @property
+    def _canonical_spec(self) -> Tuple[str, str]:
+        canonical_version = canonicalize_version(
+            self._spec[1],
+            strip_trailing_zero=(self._spec[0] != "~="),
+        )
+        return self._spec[0], canonical_version
+
+    def __hash__(self) -> int:
+        return hash(self._canonical_spec)
+
+    def __eq__(self, other: object) -> bool:
+        """Whether or not the two Specifier-like objects are equal.
+
+        :param other: The other object to check against.
+
+        The value of :attr:`prereleases` is ignored.
+
+        >>> Specifier("==1.2.3") == Specifier("== 1.2.3.0")
+        True
+        >>> (Specifier("==1.2.3", prereleases=False) ==
+        ...  Specifier("==1.2.3", prereleases=True))
+        True
+        >>> Specifier("==1.2.3") == "==1.2.3"
+        True
+        >>> Specifier("==1.2.3") == Specifier("==1.2.4")
+        False
+        >>> Specifier("==1.2.3") == Specifier("~=1.2.3")
+        False
+        """
+        if isinstance(other, str):
+            try:
+                other = self.__class__(str(other))
+            except InvalidSpecifier:
+                return NotImplemented
+        elif not isinstance(other, self.__class__):
+            return NotImplemented
+
+        return self._canonical_spec == other._canonical_spec
+
+    def _get_operator(self, op: str) -> CallableOperator:
+        operator_callable: CallableOperator = getattr(
+            self, f"_compare_{self._operators[op]}"
+        )
+        return operator_callable
+
+    def _compare_compatible(self, prospective: Version, spec: str) -> bool:
+
+        # Compatible releases have an equivalent combination of >= and ==. That
+        # is that ~=2.2 is equivalent to >=2.2,==2.*. This allows us to
+        # implement this in terms of the other specifiers instead of
+        # implementing it ourselves. The only thing we need to do is construct
+        # the other specifiers.
+
+        # We want everything but the last item in the version, but we want to
+        # ignore suffix segments.
+        prefix = ".".join(
+            list(itertools.takewhile(_is_not_suffix, _version_split(spec)))[:-1]
+        )
+
+        # Add the prefix notation to the end of our string
+        prefix += ".*"
+
+        return self._get_operator(">=")(prospective, spec) and self._get_operator("==")(
+            prospective, prefix
+        )
+
+    def _compare_equal(self, prospective: Version, spec: str) -> bool:
+
+        # We need special logic to handle prefix matching
+        if spec.endswith(".*"):
+            # In the case of prefix matching we want to ignore local segment.
+            normalized_prospective = canonicalize_version(
+                prospective.public, strip_trailing_zero=False
+            )
+            # Get the normalized version string ignoring the trailing .*
+            normalized_spec = canonicalize_version(spec[:-2], strip_trailing_zero=False)
+            # Split the spec out by dots, and pretend that there is an implicit
+            # dot in between a release segment and a pre-release segment.
+            split_spec = _version_split(normalized_spec)
+
+            # Split the prospective version out by dots, and pretend that there
+            # is an implicit dot in between a release segment and a pre-release
+            # segment.
+            split_prospective = _version_split(normalized_prospective)
+
+            # 0-pad the prospective version before shortening it to get the correct
+            # shortened version.
+            padded_prospective, _ = _pad_version(split_prospective, split_spec)
+
+            # Shorten the prospective version to be the same length as the spec
+            # so that we can determine if the specifier is a prefix of the
+            # prospective version or not.
+            shortened_prospective = padded_prospective[: len(split_spec)]
+
+            return shortened_prospective == split_spec
+        else:
+            # Convert our spec string into a Version
+            spec_version = Version(spec)
+
+            # If the specifier does not have a local segment, then we want to
+            # act as if the prospective version also does not have a local
+            # segment.
+            if not spec_version.local:
+                prospective = Version(prospective.public)
+
+            return prospective == spec_version
+
+    def _compare_not_equal(self, prospective: Version, spec: str) -> bool:
+        return not self._compare_equal(prospective, spec)
+
+    def _compare_less_than_equal(self, prospective: Version, spec: str) -> bool:
+
+        # NB: Local version identifiers are NOT permitted in the version
+        # specifier, so local version labels can be universally removed from
+        # the prospective version.
+        return Version(prospective.public) <= Version(spec)
+
+    def _compare_greater_than_equal(self, prospective: Version, spec: str) -> bool:
+
+        # NB: Local version identifiers are NOT permitted in the version
+        # specifier, so local version labels can be universally removed from
+        # the prospective version.
+        return Version(prospective.public) >= Version(spec)
+
+    def _compare_less_than(self, prospective: Version, spec_str: str) -> bool:
+
+        # Convert our spec to a Version instance, since we'll want to work with
+        # it as a version.
+        spec = Version(spec_str)
+
+        # Check to see if the prospective version is less than the spec
+        # version. If it's not we can short circuit and just return False now
+        # instead of doing extra unneeded work.
+        if not prospective < spec:
+            return False
+
+        # This special case is here so that, unless the specifier itself
+        # includes is a pre-release version, that we do not accept pre-release
+        # versions for the version mentioned in the specifier (e.g. <3.1 should
+        # not match 3.1.dev0, but should match 3.0.dev0).
+        if not spec.is_prerelease and prospective.is_prerelease:
+            if Version(prospective.base_version) == Version(spec.base_version):
+                return False
+
+        # If we've gotten to here, it means that prospective version is both
+        # less than the spec version *and* it's not a pre-release of the same
+        # version in the spec.
+        return True
+
+    def _compare_greater_than(self, prospective: Version, spec_str: str) -> bool:
+
+        # Convert our spec to a Version instance, since we'll want to work with
+        # it as a version.
+        spec = Version(spec_str)
+
+        # Check to see if the prospective version is greater than the spec
+        # version. If it's not we can short circuit and just return False now
+        # instead of doing extra unneeded work.
+        if not prospective > spec:
+            return False
+
+        # This special case is here so that, unless the specifier itself
+        # includes is a post-release version, that we do not accept
+        # post-release versions for the version mentioned in the specifier
+        # (e.g. >3.1 should not match 3.0.post0, but should match 3.2.post0).
+        if not spec.is_postrelease and prospective.is_postrelease:
+            if Version(prospective.base_version) == Version(spec.base_version):
+                return False
+
+        # Ensure that we do not allow a local version of the version mentioned
+        # in the specifier, which is technically greater than, to match.
+        if prospective.local is not None:
+            if Version(prospective.base_version) == Version(spec.base_version):
+                return False
+
+        # If we've gotten to here, it means that prospective version is both
+        # greater than the spec version *and* it's not a pre-release of the
+        # same version in the spec.
+        return True
+
+    def _compare_arbitrary(self, prospective: Version, spec: str) -> bool:
+        return str(prospective).lower() == str(spec).lower()
+
+    def __contains__(self, item: Union[str, Version]) -> bool:
+        """Return whether or not the item is contained in this specifier.
+
+        :param item: The item to check for.
+
+        This is used for the ``in`` operator and behaves the same as
+        :meth:`contains` with no ``prereleases`` argument passed.
+
+        >>> "1.2.3" in Specifier(">=1.2.3")
+        True
+        >>> Version("1.2.3") in Specifier(">=1.2.3")
+        True
+        >>> "1.0.0" in Specifier(">=1.2.3")
+        False
+        >>> "1.3.0a1" in Specifier(">=1.2.3")
+        False
+        >>> "1.3.0a1" in Specifier(">=1.2.3", prereleases=True)
+        True
+        """
+        return self.contains(item)
+
+    def contains(
+        self, item: UnparsedVersion, prereleases: Optional[bool] = None
+    ) -> bool:
+        """Return whether or not the item is contained in this specifier.
+
+        :param item:
+            The item to check for, which can be a version string or a
+            :class:`Version` instance.
+        :param prereleases:
+            Whether or not to match prereleases with this Specifier. If set to
+            ``None`` (the default), it uses :attr:`prereleases` to determine
+            whether or not prereleases are allowed.
+
+        >>> Specifier(">=1.2.3").contains("1.2.3")
+        True
+        >>> Specifier(">=1.2.3").contains(Version("1.2.3"))
+        True
+        >>> Specifier(">=1.2.3").contains("1.0.0")
+        False
+        >>> Specifier(">=1.2.3").contains("1.3.0a1")
+        False
+        >>> Specifier(">=1.2.3", prereleases=True).contains("1.3.0a1")
+        True
+        >>> Specifier(">=1.2.3").contains("1.3.0a1", prereleases=True)
+        True
+        """
+
+        # Determine if prereleases are to be allowed or not.
+        if prereleases is None:
+            prereleases = self.prereleases
+
+        # Normalize item to a Version, this allows us to have a shortcut for
+        # "2.0" in Specifier(">=2")
+        normalized_item = _coerce_version(item)
+
+        # Determine if we should be supporting prereleases in this specifier
+        # or not, if we do not support prereleases than we can short circuit
+        # logic if this version is a prereleases.
+        if normalized_item.is_prerelease and not prereleases:
+            return False
+
+        # Actually do the comparison to determine if this item is contained
+        # within this Specifier or not.
+        operator_callable: CallableOperator = self._get_operator(self.operator)
+        return operator_callable(normalized_item, self.version)
+
+    def filter(
+        self, iterable: Iterable[UnparsedVersionVar], prereleases: Optional[bool] = None
+    ) -> Iterator[UnparsedVersionVar]:
+        """Filter items in the given iterable, that match the specifier.
+
+        :param iterable:
+            An iterable that can contain version strings and :class:`Version` instances.
+            The items in the iterable will be filtered according to the specifier.
+        :param prereleases:
+            Whether or not to allow prereleases in the returned iterator. If set to
+            ``None`` (the default), it will be intelligently decide whether to allow
+            prereleases or not (based on the :attr:`prereleases` attribute, and
+            whether the only versions matching are prereleases).
+
+        This method is smarter than just ``filter(Specifier().contains, [...])``
+        because it implements the rule from :pep:`440` that a prerelease item
+        SHOULD be accepted if no other versions match the given specifier.
+
+        >>> list(Specifier(">=1.2.3").filter(["1.2", "1.3", "1.5a1"]))
+        ['1.3']
+        >>> list(Specifier(">=1.2.3").filter(["1.2", "1.2.3", "1.3", Version("1.4")]))
+        ['1.2.3', '1.3', <Version('1.4')>]
+        >>> list(Specifier(">=1.2.3").filter(["1.2", "1.5a1"]))
+        ['1.5a1']
+        >>> list(Specifier(">=1.2.3").filter(["1.3", "1.5a1"], prereleases=True))
+        ['1.3', '1.5a1']
+        >>> list(Specifier(">=1.2.3", prereleases=True).filter(["1.3", "1.5a1"]))
+        ['1.3', '1.5a1']
+        """
+
+        yielded = False
+        found_prereleases = []
+
+        kw = {"prereleases": prereleases if prereleases is not None else True}
+
+        # Attempt to iterate over all the values in the iterable and if any of
+        # them match, yield them.
+        for version in iterable:
+            parsed_version = _coerce_version(version)
+
+            if self.contains(parsed_version, **kw):
+                # If our version is a prerelease, and we were not set to allow
+                # prereleases, then we'll store it for later in case nothing
+                # else matches this specifier.
+                if parsed_version.is_prerelease and not (
+                    prereleases or self.prereleases
+                ):
+                    found_prereleases.append(version)
+                # Either this is not a prerelease, or we should have been
+                # accepting prereleases from the beginning.
+                else:
+                    yielded = True
+                    yield version
+
+        # Now that we've iterated over everything, determine if we've yielded
+        # any values, and if we have not and we have any prereleases stored up
+        # then we will go ahead and yield the prereleases.
+        if not yielded and found_prereleases:
+            for version in found_prereleases:
+                yield version
+
+
+_prefix_regex = re.compile(r"^([0-9]+)((?:a|b|c|rc)[0-9]+)$")
+
+
+def _version_split(version: str) -> List[str]:
+    result: List[str] = []
+    for item in version.split("."):
+        match = _prefix_regex.search(item)
+        if match:
+            result.extend(match.groups())
+        else:
+            result.append(item)
+    return result
+
+
+def _is_not_suffix(segment: str) -> bool:
+    return not any(
+        segment.startswith(prefix) for prefix in ("dev", "a", "b", "rc", "post")
+    )
+
+
+def _pad_version(left: List[str], right: List[str]) -> Tuple[List[str], List[str]]:
+    left_split, right_split = [], []
+
+    # Get the release segment of our versions
+    left_split.append(list(itertools.takewhile(lambda x: x.isdigit(), left)))
+    right_split.append(list(itertools.takewhile(lambda x: x.isdigit(), right)))
+
+    # Get the rest of our versions
+    left_split.append(left[len(left_split[0]) :])
+    right_split.append(right[len(right_split[0]) :])
+
+    # Insert our padding
+    left_split.insert(1, ["0"] * max(0, len(right_split[0]) - len(left_split[0])))
+    right_split.insert(1, ["0"] * max(0, len(left_split[0]) - len(right_split[0])))
+
+    return (list(itertools.chain(*left_split)), list(itertools.chain(*right_split)))
+
+
+class SpecifierSet(BaseSpecifier):
+    """This class abstracts handling of a set of version specifiers.
+
+    It can be passed a single specifier (``>=3.0``), a comma-separated list of
+    specifiers (``>=3.0,!=3.1``), or no specifier at all.
+    """
+
+    def __init__(
+        self, specifiers: str = "", prereleases: Optional[bool] = None
+    ) -> None:
+        """Initialize a SpecifierSet instance.
+
+        :param specifiers:
+            The string representation of a specifier or a comma-separated list of
+            specifiers which will be parsed and normalized before use.
+        :param prereleases:
+            This tells the SpecifierSet if it should accept prerelease versions if
+            applicable or not. The default of ``None`` will autodetect it from the
+            given specifiers.
+
+        :raises InvalidSpecifier:
+            If the given ``specifiers`` are not parseable than this exception will be
+            raised.
+        """
+
+        # Split on `,` to break each individual specifier into it's own item, and
+        # strip each item to remove leading/trailing whitespace.
+        split_specifiers = [s.strip() for s in specifiers.split(",") if s.strip()]
+
+        # Parsed each individual specifier, attempting first to make it a
+        # Specifier.
+        parsed: Set[Specifier] = set()
+        for specifier in split_specifiers:
+            parsed.add(Specifier(specifier))
+
+        # Turn our parsed specifiers into a frozen set and save them for later.
+        self._specs = frozenset(parsed)
+
+        # Store our prereleases value so we can use it later to determine if
+        # we accept prereleases or not.
+        self._prereleases = prereleases
+
+    @property
+    def prereleases(self) -> Optional[bool]:
+        # If we have been given an explicit prerelease modifier, then we'll
+        # pass that through here.
+        if self._prereleases is not None:
+            return self._prereleases
+
+        # If we don't have any specifiers, and we don't have a forced value,
+        # then we'll just return None since we don't know if this should have
+        # pre-releases or not.
+        if not self._specs:
+            return None
+
+        # Otherwise we'll see if any of the given specifiers accept
+        # prereleases, if any of them do we'll return True, otherwise False.
+        return any(s.prereleases for s in self._specs)
+
+    @prereleases.setter
+    def prereleases(self, value: bool) -> None:
+        self._prereleases = value
+
+    def __repr__(self) -> str:
+        """A representation of the specifier set that shows all internal state.
+
+        Note that the ordering of the individual specifiers within the set may not
+        match the input string.
+
+        >>> SpecifierSet('>=1.0.0,!=2.0.0')
+        <SpecifierSet('!=2.0.0,>=1.0.0')>
+        >>> SpecifierSet('>=1.0.0,!=2.0.0', prereleases=False)
+        <SpecifierSet('!=2.0.0,>=1.0.0', prereleases=False)>
+        >>> SpecifierSet('>=1.0.0,!=2.0.0', prereleases=True)
+        <SpecifierSet('!=2.0.0,>=1.0.0', prereleases=True)>
+        """
+        pre = (
+            f", prereleases={self.prereleases!r}"
+            if self._prereleases is not None
+            else ""
+        )
+
+        return f"<SpecifierSet({str(self)!r}{pre})>"
+
+    def __str__(self) -> str:
+        """A string representation of the specifier set that can be round-tripped.
+
+        Note that the ordering of the individual specifiers within the set may not
+        match the input string.
+
+        >>> str(SpecifierSet(">=1.0.0,!=1.0.1"))
+        '!=1.0.1,>=1.0.0'
+        >>> str(SpecifierSet(">=1.0.0,!=1.0.1", prereleases=False))
+        '!=1.0.1,>=1.0.0'
+        """
+        return ",".join(sorted(str(s) for s in self._specs))
+
+    def __hash__(self) -> int:
+        return hash(self._specs)
+
+    def __and__(self, other: Union["SpecifierSet", str]) -> "SpecifierSet":
+        """Return a SpecifierSet which is a combination of the two sets.
+
+        :param other: The other object to combine with.
+
+        >>> SpecifierSet(">=1.0.0,!=1.0.1") & '<=2.0.0,!=2.0.1'
+        <SpecifierSet('!=1.0.1,!=2.0.1,<=2.0.0,>=1.0.0')>
+        >>> SpecifierSet(">=1.0.0,!=1.0.1") & SpecifierSet('<=2.0.0,!=2.0.1')
+        <SpecifierSet('!=1.0.1,!=2.0.1,<=2.0.0,>=1.0.0')>
+        """
+        if isinstance(other, str):
+            other = SpecifierSet(other)
+        elif not isinstance(other, SpecifierSet):
+            return NotImplemented
+
+        specifier = SpecifierSet()
+        specifier._specs = frozenset(self._specs | other._specs)
+
+        if self._prereleases is None and other._prereleases is not None:
+            specifier._prereleases = other._prereleases
+        elif self._prereleases is not None and other._prereleases is None:
+            specifier._prereleases = self._prereleases
+        elif self._prereleases == other._prereleases:
+            specifier._prereleases = self._prereleases
+        else:
+            raise ValueError(
+                "Cannot combine SpecifierSets with True and False prerelease "
+                "overrides."
+            )
+
+        return specifier
+
+    def __eq__(self, other: object) -> bool:
+        """Whether or not the two SpecifierSet-like objects are equal.
+
+        :param other: The other object to check against.
+
+        The value of :attr:`prereleases` is ignored.
+
+        >>> SpecifierSet(">=1.0.0,!=1.0.1") == SpecifierSet(">=1.0.0,!=1.0.1")
+        True
+        >>> (SpecifierSet(">=1.0.0,!=1.0.1", prereleases=False) ==
+        ...  SpecifierSet(">=1.0.0,!=1.0.1", prereleases=True))
+        True
+        >>> SpecifierSet(">=1.0.0,!=1.0.1") == ">=1.0.0,!=1.0.1"
+        True
+        >>> SpecifierSet(">=1.0.0,!=1.0.1") == SpecifierSet(">=1.0.0")
+        False
+        >>> SpecifierSet(">=1.0.0,!=1.0.1") == SpecifierSet(">=1.0.0,!=1.0.2")
+        False
+        """
+        if isinstance(other, (str, Specifier)):
+            other = SpecifierSet(str(other))
+        elif not isinstance(other, SpecifierSet):
+            return NotImplemented
+
+        return self._specs == other._specs
+
+    def __len__(self) -> int:
+        """Returns the number of specifiers in this specifier set."""
+        return len(self._specs)
+
+    def __iter__(self) -> Iterator[Specifier]:
+        """
+        Returns an iterator over all the underlying :class:`Specifier` instances
+        in this specifier set.
+
+        >>> sorted(SpecifierSet(">=1.0.0,!=1.0.1"), key=str)
+        [<Specifier('!=1.0.1')>, <Specifier('>=1.0.0')>]
+        """
+        return iter(self._specs)
+
+    def __contains__(self, item: UnparsedVersion) -> bool:
+        """Return whether or not the item is contained in this specifier.
+
+        :param item: The item to check for.
+
+        This is used for the ``in`` operator and behaves the same as
+        :meth:`contains` with no ``prereleases`` argument passed.
+
+        >>> "1.2.3" in SpecifierSet(">=1.0.0,!=1.0.1")
+        True
+        >>> Version("1.2.3") in SpecifierSet(">=1.0.0,!=1.0.1")
+        True
+        >>> "1.0.1" in SpecifierSet(">=1.0.0,!=1.0.1")
+        False
+        >>> "1.3.0a1" in SpecifierSet(">=1.0.0,!=1.0.1")
+        False
+        >>> "1.3.0a1" in SpecifierSet(">=1.0.0,!=1.0.1", prereleases=True)
+        True
+        """
+        return self.contains(item)
+
+    def contains(
+        self,
+        item: UnparsedVersion,
+        prereleases: Optional[bool] = None,
+        installed: Optional[bool] = None,
+    ) -> bool:
+        """Return whether or not the item is contained in this SpecifierSet.
+
+        :param item:
+            The item to check for, which can be a version string or a
+            :class:`Version` instance.
+        :param prereleases:
+            Whether or not to match prereleases with this SpecifierSet. If set to
+            ``None`` (the default), it uses :attr:`prereleases` to determine
+            whether or not prereleases are allowed.
+
+        >>> SpecifierSet(">=1.0.0,!=1.0.1").contains("1.2.3")
+        True
+        >>> SpecifierSet(">=1.0.0,!=1.0.1").contains(Version("1.2.3"))
+        True
+        >>> SpecifierSet(">=1.0.0,!=1.0.1").contains("1.0.1")
+        False
+        >>> SpecifierSet(">=1.0.0,!=1.0.1").contains("1.3.0a1")
+        False
+        >>> SpecifierSet(">=1.0.0,!=1.0.1", prereleases=True).contains("1.3.0a1")
+        True
+        >>> SpecifierSet(">=1.0.0,!=1.0.1").contains("1.3.0a1", prereleases=True)
+        True
+        """
+        # Ensure that our item is a Version instance.
+        if not isinstance(item, Version):
+            item = Version(item)
+
+        # Determine if we're forcing a prerelease or not, if we're not forcing
+        # one for this particular filter call, then we'll use whatever the
+        # SpecifierSet thinks for whether or not we should support prereleases.
+        if prereleases is None:
+            prereleases = self.prereleases
+
+        # We can determine if we're going to allow pre-releases by looking to
+        # see if any of the underlying items supports them. If none of them do
+        # and this item is a pre-release then we do not allow it and we can
+        # short circuit that here.
+        # Note: This means that 1.0.dev1 would not be contained in something
+        #       like >=1.0.devabc however it would be in >=1.0.debabc,>0.0.dev0
+        if not prereleases and item.is_prerelease:
+            return False
+
+        if installed and item.is_prerelease:
+            item = Version(item.base_version)
+
+        # We simply dispatch to the underlying specs here to make sure that the
+        # given version is contained within all of them.
+        # Note: This use of all() here means that an empty set of specifiers
+        #       will always return True, this is an explicit design decision.
+        return all(s.contains(item, prereleases=prereleases) for s in self._specs)
+
+    def filter(
+        self, iterable: Iterable[UnparsedVersionVar], prereleases: Optional[bool] = None
+    ) -> Iterator[UnparsedVersionVar]:
+        """Filter items in the given iterable, that match the specifiers in this set.
+
+        :param iterable:
+            An iterable that can contain version strings and :class:`Version` instances.
+            The items in the iterable will be filtered according to the specifier.
+        :param prereleases:
+            Whether or not to allow prereleases in the returned iterator. If set to
+            ``None`` (the default), it will be intelligently decide whether to allow
+            prereleases or not (based on the :attr:`prereleases` attribute, and
+            whether the only versions matching are prereleases).
+
+        This method is smarter than just ``filter(SpecifierSet(...).contains, [...])``
+        because it implements the rule from :pep:`440` that a prerelease item
+        SHOULD be accepted if no other versions match the given specifier.
+
+        >>> list(SpecifierSet(">=1.2.3").filter(["1.2", "1.3", "1.5a1"]))
+        ['1.3']
+        >>> list(SpecifierSet(">=1.2.3").filter(["1.2", "1.3", Version("1.4")]))
+        ['1.3', <Version('1.4')>]
+        >>> list(SpecifierSet(">=1.2.3").filter(["1.2", "1.5a1"]))
+        []
+        >>> list(SpecifierSet(">=1.2.3").filter(["1.3", "1.5a1"], prereleases=True))
+        ['1.3', '1.5a1']
+        >>> list(SpecifierSet(">=1.2.3", prereleases=True).filter(["1.3", "1.5a1"]))
+        ['1.3', '1.5a1']
+
+        An "empty" SpecifierSet will filter items based on the presence of prerelease
+        versions in the set.
+
+        >>> list(SpecifierSet("").filter(["1.3", "1.5a1"]))
+        ['1.3']
+        >>> list(SpecifierSet("").filter(["1.5a1"]))
+        ['1.5a1']
+        >>> list(SpecifierSet("", prereleases=True).filter(["1.3", "1.5a1"]))
+        ['1.3', '1.5a1']
+        >>> list(SpecifierSet("").filter(["1.3", "1.5a1"], prereleases=True))
+        ['1.3', '1.5a1']
+        """
+        # Determine if we're forcing a prerelease or not, if we're not forcing
+        # one for this particular filter call, then we'll use whatever the
+        # SpecifierSet thinks for whether or not we should support prereleases.
+        if prereleases is None:
+            prereleases = self.prereleases
+
+        # If we have any specifiers, then we want to wrap our iterable in the
+        # filter method for each one, this will act as a logical AND amongst
+        # each specifier.
+        if self._specs:
+            for spec in self._specs:
+                iterable = spec.filter(iterable, prereleases=bool(prereleases))
+            return iter(iterable)
+        # If we do not have any specifiers, then we need to have a rough filter
+        # which will filter out any pre-releases, unless there are no final
+        # releases.
+        else:
+            filtered: List[UnparsedVersionVar] = []
+            found_prereleases: List[UnparsedVersionVar] = []
+
+            for item in iterable:
+                parsed_version = _coerce_version(item)
+
+                # Store any item which is a pre-release for later unless we've
+                # already found a final version or we are accepting prereleases
+                if parsed_version.is_prerelease and not prereleases:
+                    if not filtered:
+                        found_prereleases.append(item)
+                else:
+                    filtered.append(item)
+
+            # If we've found no items except for pre-releases, then we'll go
+            # ahead and use the pre-releases
+            if not filtered and found_prereleases and prereleases is None:
+                return iter(found_prereleases)
+
+            return iter(filtered)
diff --git a/third_party/python/setuptools/pkg_resources/_vendor/packaging/tags.py b/third_party/python/setuptools/pkg_resources/_vendor/packaging/tags.py
new file mode 100644
index 0000000000..76d243414d
--- /dev/null
+++ b/third_party/python/setuptools/pkg_resources/_vendor/packaging/tags.py
@@ -0,0 +1,546 @@
+# This file is dual licensed under the terms of the Apache License, Version
+# 2.0, and the BSD License. See the LICENSE file in the root of this repository
+# for complete details.
+
+import logging
+import platform
+import subprocess
+import sys
+import sysconfig
+from importlib.machinery import EXTENSION_SUFFIXES
+from typing import (
+    Dict,
+    FrozenSet,
+    Iterable,
+    Iterator,
+    List,
+    Optional,
+    Sequence,
+    Tuple,
+    Union,
+    cast,
+)
+
+from . import _manylinux, _musllinux
+
+logger = logging.getLogger(__name__)
+
+PythonVersion = Sequence[int]
+MacVersion = Tuple[int, int]
+
+INTERPRETER_SHORT_NAMES: Dict[str, str] = {
+    "python": "py",  # Generic.
+    "cpython": "cp",
+    "pypy": "pp",
+    "ironpython": "ip",
+    "jython": "jy",
+}
+
+
+_32_BIT_INTERPRETER = sys.maxsize <= 2**32
+
+
+class Tag:
+    """
+    A representation of the tag triple for a wheel.
+
+    Instances are considered immutable and thus are hashable. Equality checking
+    is also supported.
+    """
+
+    __slots__ = ["_interpreter", "_abi", "_platform", "_hash"]
+
+    def __init__(self, interpreter: str, abi: str, platform: str) -> None:
+        self._interpreter = interpreter.lower()
+        self._abi = abi.lower()
+        self._platform = platform.lower()
+        # The __hash__ of every single element in a Set[Tag] will be evaluated each time
+        # that a set calls its `.disjoint()` method, which may be called hundreds of
+        # times when scanning a page of links for packages with tags matching that
+        # Set[Tag]. Pre-computing the value here produces significant speedups for
+        # downstream consumers.
+        self._hash = hash((self._interpreter, self._abi, self._platform))
+
+    @property
+    def interpreter(self) -> str:
+        return self._interpreter
+
+    @property
+    def abi(self) -> str:
+        return self._abi
+
+    @property
+    def platform(self) -> str:
+        return self._platform
+
+    def __eq__(self, other: object) -> bool:
+        if not isinstance(other, Tag):
+            return NotImplemented
+
+        return (
+            (self._hash == other._hash)  # Short-circuit ASAP for perf reasons.
+            and (self._platform == other._platform)
+            and (self._abi == other._abi)
+            and (self._interpreter == other._interpreter)
+        )
+
+    def __hash__(self) -> int:
+        return self._hash
+
+    def __str__(self) -> str:
+        return f"{self._interpreter}-{self._abi}-{self._platform}"
+
+    def __repr__(self) -> str:
+        return f"<{self} @ {id(self)}>"
+
+
+def parse_tag(tag: str) -> FrozenSet[Tag]:
+    """
+    Parses the provided tag (e.g. `py3-none-any`) into a frozenset of Tag instances.
+
+    Returning a set is required due to the possibility that the tag is a
+    compressed tag set.
+    """
+    tags = set()
+    interpreters, abis, platforms = tag.split("-")
+    for interpreter in interpreters.split("."):
+        for abi in abis.split("."):
+            for platform_ in platforms.split("."):
+                tags.add(Tag(interpreter, abi, platform_))
+    return frozenset(tags)
+
+
+def _get_config_var(name: str, warn: bool = False) -> Union[int, str, None]:
+    value: Union[int, str, None] = sysconfig.get_config_var(name)
+    if value is None and warn:
+        logger.debug(
+            "Config variable '%s' is unset, Python ABI tag may be incorrect", name
+        )
+    return value
+
+
+def _normalize_string(string: str) -> str:
+    return string.replace(".", "_").replace("-", "_").replace(" ", "_")
+
+
+def _abi3_applies(python_version: PythonVersion) -> bool:
+    """
+    Determine if the Python version supports abi3.
+
+    PEP 384 was first implemented in Python 3.2.
+    """
+    return len(python_version) > 1 and tuple(python_version) >= (3, 2)
+
+
+def _cpython_abis(py_version: PythonVersion, warn: bool = False) -> List[str]:
+    py_version = tuple(py_version)  # To allow for version comparison.
+    abis = []
+    version = _version_nodot(py_version[:2])
+    debug = pymalloc = ucs4 = ""
+    with_debug = _get_config_var("Py_DEBUG", warn)
+    has_refcount = hasattr(sys, "gettotalrefcount")
+    # Windows doesn't set Py_DEBUG, so checking for support of debug-compiled
+    # extension modules is the best option.
+    # https://github.com/pypa/pip/issues/3383#issuecomment-173267692
+    has_ext = "_d.pyd" in EXTENSION_SUFFIXES
+    if with_debug or (with_debug is None and (has_refcount or has_ext)):
+        debug = "d"
+    if py_version < (3, 8):
+        with_pymalloc = _get_config_var("WITH_PYMALLOC", warn)
+        if with_pymalloc or with_pymalloc is None:
+            pymalloc = "m"
+        if py_version < (3, 3):
+            unicode_size = _get_config_var("Py_UNICODE_SIZE", warn)
+            if unicode_size == 4 or (
+                unicode_size is None and sys.maxunicode == 0x10FFFF
+            ):
+                ucs4 = "u"
+    elif debug:
+        # Debug builds can also load "normal" extension modules.
+        # We can also assume no UCS-4 or pymalloc requirement.
+        abis.append(f"cp{version}")
+    abis.insert(
+        0,
+        "cp{version}{debug}{pymalloc}{ucs4}".format(
+            version=version, debug=debug, pymalloc=pymalloc, ucs4=ucs4
+        ),
+    )
+    return abis
+
+
+def cpython_tags(
+    python_version: Optional[PythonVersion] = None,
+    abis: Optional[Iterable[str]] = None,
+    platforms: Optional[Iterable[str]] = None,
+    *,
+    warn: bool = False,
+) -> Iterator[Tag]:
+    """
+    Yields the tags for a CPython interpreter.
+
+    The tags consist of:
+    - cp<python_version>-<abi>-<platform>
+    - cp<python_version>-abi3-<platform>
+    - cp<python_version>-none-<platform>
+    - cp<less than python_version>-abi3-<platform>  # Older Python versions down to 3.2.
+
+    If python_version only specifies a major version then user-provided ABIs and
+    the 'none' ABItag will be used.
+
+    If 'abi3' or 'none' are specified in 'abis' then they will be yielded at
+    their normal position and not at the beginning.
+    """
+    if not python_version:
+        python_version = sys.version_info[:2]
+
+    interpreter = f"cp{_version_nodot(python_version[:2])}"
+
+    if abis is None:
+        if len(python_version) > 1:
+            abis = _cpython_abis(python_version, warn)
+        else:
+            abis = []
+    abis = list(abis)
+    # 'abi3' and 'none' are explicitly handled later.
+    for explicit_abi in ("abi3", "none"):
+        try:
+            abis.remove(explicit_abi)
+        except ValueError:
+            pass
+
+    platforms = list(platforms or platform_tags())
+    for abi in abis:
+        for platform_ in platforms:
+            yield Tag(interpreter, abi, platform_)
+    if _abi3_applies(python_version):
+        yield from (Tag(interpreter, "abi3", platform_) for platform_ in platforms)
+    yield from (Tag(interpreter, "none", platform_) for platform_ in platforms)
+
+    if _abi3_applies(python_version):
+        for minor_version in range(python_version[1] - 1, 1, -1):
+            for platform_ in platforms:
+                interpreter = "cp{version}".format(
+                    version=_version_nodot((python_version[0], minor_version))
+                )
+                yield Tag(interpreter, "abi3", platform_)
+
+
+def _generic_abi() -> List[str]:
+    """
+    Return the ABI tag based on EXT_SUFFIX.
+    """
+    # The following are examples of `EXT_SUFFIX`.
+    # We want to keep the parts which are related to the ABI and remove the
+    # parts which are related to the platform:
+    # - linux:   '.cpython-310-x86_64-linux-gnu.so' => cp310
+    # - mac:     '.cpython-310-darwin.so'           => cp310
+    # - win:     '.cp310-win_amd64.pyd'             => cp310
+    # - win:     '.pyd'                             => cp37 (uses _cpython_abis())
+    # - pypy:    '.pypy38-pp73-x86_64-linux-gnu.so' => pypy38_pp73
+    # - graalpy: '.graalpy-38-native-x86_64-darwin.dylib'
+    #                                               => graalpy_38_native
+
+    ext_suffix = _get_config_var("EXT_SUFFIX", warn=True)
+    if not isinstance(ext_suffix, str) or ext_suffix[0] != ".":
+        raise SystemError("invalid sysconfig.get_config_var('EXT_SUFFIX')")
+    parts = ext_suffix.split(".")
+    if len(parts) < 3:
+        # CPython3.7 and earlier uses ".pyd" on Windows.
+        return _cpython_abis(sys.version_info[:2])
+    soabi = parts[1]
+    if soabi.startswith("cpython"):
+        # non-windows
+        abi = "cp" + soabi.split("-")[1]
+    elif soabi.startswith("cp"):
+        # windows
+        abi = soabi.split("-")[0]
+    elif soabi.startswith("pypy"):
+        abi = "-".join(soabi.split("-")[:2])
+    elif soabi.startswith("graalpy"):
+        abi = "-".join(soabi.split("-")[:3])
+    elif soabi:
+        # pyston, ironpython, others?
+        abi = soabi
+    else:
+        return []
+    return [_normalize_string(abi)]
+
+
+def generic_tags(
+    interpreter: Optional[str] = None,
+    abis: Optional[Iterable[str]] = None,
+    platforms: Optional[Iterable[str]] = None,
+    *,
+    warn: bool = False,
+) -> Iterator[Tag]:
+    """
+    Yields the tags for a generic interpreter.
+
+    The tags consist of:
+    - <interpreter>-<abi>-<platform>
+
+    The "none" ABI will be added if it was not explicitly provided.
+    """
+    if not interpreter:
+        interp_name = interpreter_name()
+        interp_version = interpreter_version(warn=warn)
+        interpreter = "".join([interp_name, interp_version])
+    if abis is None:
+        abis = _generic_abi()
+    else:
+        abis = list(abis)
+    platforms = list(platforms or platform_tags())
+    if "none" not in abis:
+        abis.append("none")
+    for abi in abis:
+        for platform_ in platforms:
+            yield Tag(interpreter, abi, platform_)
+
+
+def _py_interpreter_range(py_version: PythonVersion) -> Iterator[str]:
+    """
+    Yields Python versions in descending order.
+
+    After the latest version, the major-only version will be yielded, and then
+    all previous versions of that major version.
+    """
+    if len(py_version) > 1:
+        yield f"py{_version_nodot(py_version[:2])}"
+    yield f"py{py_version[0]}"
+    if len(py_version) > 1:
+        for minor in range(py_version[1] - 1, -1, -1):
+            yield f"py{_version_nodot((py_version[0], minor))}"
+
+
+def compatible_tags(
+    python_version: Optional[PythonVersion] = None,
+    interpreter: Optional[str] = None,
+    platforms: Optional[Iterable[str]] = None,
+) -> Iterator[Tag]:
+    """
+    Yields the sequence of tags that are compatible with a specific version of Python.
+
+    The tags consist of:
+    - py*-none-<platform>
+    - <interpreter>-none-any  # ... if `interpreter` is provided.
+    - py*-none-any
+    """
+    if not python_version:
+        python_version = sys.version_info[:2]
+    platforms = list(platforms or platform_tags())
+    for version in _py_interpreter_range(python_version):
+        for platform_ in platforms:
+            yield Tag(version, "none", platform_)
+    if interpreter:
+        yield Tag(interpreter, "none", "any")
+    for version in _py_interpreter_range(python_version):
+        yield Tag(version, "none", "any")
+
+
+def _mac_arch(arch: str, is_32bit: bool = _32_BIT_INTERPRETER) -> str:
+    if not is_32bit:
+        return arch
+
+    if arch.startswith("ppc"):
+        return "ppc"
+
+    return "i386"
+
+
+def _mac_binary_formats(version: MacVersion, cpu_arch: str) -> List[str]:
+    formats = [cpu_arch]
+    if cpu_arch == "x86_64":
+        if version < (10, 4):
+            return []
+        formats.extend(["intel", "fat64", "fat32"])
+
+    elif cpu_arch == "i386":
+        if version < (10, 4):
+            return []
+        formats.extend(["intel", "fat32", "fat"])
+
+    elif cpu_arch == "ppc64":
+        # TODO: Need to care about 32-bit PPC for ppc64 through 10.2?
+        if version > (10, 5) or version < (10, 4):
+            return []
+        formats.append("fat64")
+
+    elif cpu_arch == "ppc":
+        if version > (10, 6):
+            return []
+        formats.extend(["fat32", "fat"])
+
+    if cpu_arch in {"arm64", "x86_64"}:
+        formats.append("universal2")
+
+    if cpu_arch in {"x86_64", "i386", "ppc64", "ppc", "intel"}:
+        formats.append("universal")
+
+    return formats
+
+
+def mac_platforms(
+    version: Optional[MacVersion] = None, arch: Optional[str] = None
+) -> Iterator[str]:
+    """
+    Yields the platform tags for a macOS system.
+
+    The `version` parameter is a two-item tuple specifying the macOS version to
+    generate platform tags for. The `arch` parameter is the CPU architecture to
+    generate platform tags for. Both parameters default to the appropriate value
+    for the current system.
+    """
+    version_str, _, cpu_arch = platform.mac_ver()
+    if version is None:
+        version = cast("MacVersion", tuple(map(int, version_str.split(".")[:2])))
+        if version == (10, 16):
+            # When built against an older macOS SDK, Python will report macOS 10.16
+            # instead of the real version.
+            version_str = subprocess.run(
+                [
+                    sys.executable,
+                    "-sS",
+                    "-c",
+                    "import platform; print(platform.mac_ver()[0])",
+                ],
+                check=True,
+                env={"SYSTEM_VERSION_COMPAT": "0"},
+                stdout=subprocess.PIPE,
+                universal_newlines=True,
+            ).stdout
+            version = cast("MacVersion", tuple(map(int, version_str.split(".")[:2])))
+    else:
+        version = version
+    if arch is None:
+        arch = _mac_arch(cpu_arch)
+    else:
+        arch = arch
+
+    if (10, 0) <= version and version < (11, 0):
+        # Prior to Mac OS 11, each yearly release of Mac OS bumped the
+        # "minor" version number.  The major version was always 10.
+        for minor_version in range(version[1], -1, -1):
+            compat_version = 10, minor_version
+            binary_formats = _mac_binary_formats(compat_version, arch)
+            for binary_format in binary_formats:
+                yield "macosx_{major}_{minor}_{binary_format}".format(
+                    major=10, minor=minor_version, binary_format=binary_format
+                )
+
+    if version >= (11, 0):
+        # Starting with Mac OS 11, each yearly release bumps the major version
+        # number.   The minor versions are now the midyear updates.
+        for major_version in range(version[0], 10, -1):
+            compat_version = major_version, 0
+            binary_formats = _mac_binary_formats(compat_version, arch)
+            for binary_format in binary_formats:
+                yield "macosx_{major}_{minor}_{binary_format}".format(
+                    major=major_version, minor=0, binary_format=binary_format
+                )
+
+    if version >= (11, 0):
+        # Mac OS 11 on x86_64 is compatible with binaries from previous releases.
+        # Arm64 support was introduced in 11.0, so no Arm binaries from previous
+        # releases exist.
+        #
+        # However, the "universal2" binary format can have a
+        # macOS version earlier than 11.0 when the x86_64 part of the binary supports
+        # that version of macOS.
+        if arch == "x86_64":
+            for minor_version in range(16, 3, -1):
+                compat_version = 10, minor_version
+                binary_formats = _mac_binary_formats(compat_version, arch)
+                for binary_format in binary_formats:
+                    yield "macosx_{major}_{minor}_{binary_format}".format(
+                        major=compat_version[0],
+                        minor=compat_version[1],
+                        binary_format=binary_format,
+                    )
+        else:
+            for minor_version in range(16, 3, -1):
+                compat_version = 10, minor_version
+                binary_format = "universal2"
+                yield "macosx_{major}_{minor}_{binary_format}".format(
+                    major=compat_version[0],
+                    minor=compat_version[1],
+                    binary_format=binary_format,
+                )
+
+
+def _linux_platforms(is_32bit: bool = _32_BIT_INTERPRETER) -> Iterator[str]:
+    linux = _normalize_string(sysconfig.get_platform())
+    if is_32bit:
+        if linux == "linux_x86_64":
+            linux = "linux_i686"
+        elif linux == "linux_aarch64":
+            linux = "linux_armv7l"
+    _, arch = linux.split("_", 1)
+    yield from _manylinux.platform_tags(linux, arch)
+    yield from _musllinux.platform_tags(arch)
+    yield linux
+
+
+def _generic_platforms() -> Iterator[str]:
+    yield _normalize_string(sysconfig.get_platform())
+
+
+def platform_tags() -> Iterator[str]:
+    """
+    Provides the platform tags for this installation.
+    """
+    if platform.system() == "Darwin":
+        return mac_platforms()
+    elif platform.system() == "Linux":
+        return _linux_platforms()
+    else:
+        return _generic_platforms()
+
+
+def interpreter_name() -> str:
+    """
+    Returns the name of the running interpreter.
+
+    Some implementations have a reserved, two-letter abbreviation which will
+    be returned when appropriate.
+    """
+    name = sys.implementation.name
+    return INTERPRETER_SHORT_NAMES.get(name) or name
+
+
+def interpreter_version(*, warn: bool = False) -> str:
+    """
+    Returns the version of the running interpreter.
+    """
+    version = _get_config_var("py_version_nodot", warn=warn)
+    if version:
+        version = str(version)
+    else:
+        version = _version_nodot(sys.version_info[:2])
+    return version
+
+
+def _version_nodot(version: PythonVersion) -> str:
+    return "".join(map(str, version))
+
+
+def sys_tags(*, warn: bool = False) -> Iterator[Tag]:
+    """
+    Returns the sequence of tag triples for the running interpreter.
+
+    The order of the sequence corresponds to priority order for the
+    interpreter, from most to least important.
+    """
+
+    interp_name = interpreter_name()
+    if interp_name == "cp":
+        yield from cpython_tags(warn=warn)
+    else:
+        yield from generic_tags()
+
+    if interp_name == "pp":
+        interp = "pp3"
+    elif interp_name == "cp":
+        interp = "cp" + interpreter_version(warn=warn)
+    else:
+        interp = None
+    yield from compatible_tags(interpreter=interp)
diff --git a/third_party/python/setuptools/pkg_resources/_vendor/packaging/utils.py b/third_party/python/setuptools/pkg_resources/_vendor/packaging/utils.py
new file mode 100644
index 0000000000..33c613b749
--- /dev/null
+++ b/third_party/python/setuptools/pkg_resources/_vendor/packaging/utils.py
@@ -0,0 +1,141 @@
+# This file is dual licensed under the terms of the Apache License, Version
+# 2.0, and the BSD License. See the LICENSE file in the root of this repository
+# for complete details.
+
+import re
+from typing import FrozenSet, NewType, Tuple, Union, cast
+
+from .tags import Tag, parse_tag
+from .version import InvalidVersion, Version
+
+BuildTag = Union[Tuple[()], Tuple[int, str]]
+NormalizedName = NewType("NormalizedName", str)
+
+
+class InvalidWheelFilename(ValueError):
+    """
+    An invalid wheel filename was found, users should refer to PEP 427.
+    """
+
+
+class InvalidSdistFilename(ValueError):
+    """
+    An invalid sdist filename was found, users should refer to the packaging user guide.
+    """
+
+
+_canonicalize_regex = re.compile(r"[-_.]+")
+# PEP 427: The build number must start with a digit.
+_build_tag_regex = re.compile(r"(\d+)(.*)")
+
+
+def canonicalize_name(name: str) -> NormalizedName:
+    # This is taken from PEP 503.
+    value = _canonicalize_regex.sub("-", name).lower()
+    return cast(NormalizedName, value)
+
+
+def canonicalize_version(
+    version: Union[Version, str], *, strip_trailing_zero: bool = True
+) -> str:
+    """
+    This is very similar to Version.__str__, but has one subtle difference
+    with the way it handles the release segment.
+    """
+    if isinstance(version, str):
+        try:
+            parsed = Version(version)
+        except InvalidVersion:
+            # Legacy versions cannot be normalized
+            return version
+    else:
+        parsed = version
+
+    parts = []
+
+    # Epoch
+    if parsed.epoch != 0:
+        parts.append(f"{parsed.epoch}!")
+
+    # Release segment
+    release_segment = ".".join(str(x) for x in parsed.release)
+    if strip_trailing_zero:
+        # NB: This strips trailing '.0's to normalize
+        release_segment = re.sub(r"(\.0)+$", "", release_segment)
+    parts.append(release_segment)
+
+    # Pre-release
+    if parsed.pre is not None:
+        parts.append("".join(str(x) for x in parsed.pre))
+
+    # Post-release
+    if parsed.post is not None:
+        parts.append(f".post{parsed.post}")
+
+    # Development release
+    if parsed.dev is not None:
+        parts.append(f".dev{parsed.dev}")
+
+    # Local version segment
+    if parsed.local is not None:
+        parts.append(f"+{parsed.local}")
+
+    return "".join(parts)
+
+
+def parse_wheel_filename(
+    filename: str,
+) -> Tuple[NormalizedName, Version, BuildTag, FrozenSet[Tag]]:
+    if not filename.endswith(".whl"):
+        raise InvalidWheelFilename(
+            f"Invalid wheel filename (extension must be '.whl'): {filename}"
+        )
+
+    filename = filename[:-4]
+    dashes = filename.count("-")
+    if dashes not in (4, 5):
+        raise InvalidWheelFilename(
+            f"Invalid wheel filename (wrong number of parts): {filename}"
+        )
+
+    parts = filename.split("-", dashes - 2)
+    name_part = parts[0]
+    # See PEP 427 for the rules on escaping the project name
+    if "__" in name_part or re.match(r"^[\w\d._]*$", name_part, re.UNICODE) is None:
+        raise InvalidWheelFilename(f"Invalid project name: {filename}")
+    name = canonicalize_name(name_part)
+    version = Version(parts[1])
+    if dashes == 5:
+        build_part = parts[2]
+        build_match = _build_tag_regex.match(build_part)
+        if build_match is None:
+            raise InvalidWheelFilename(
+                f"Invalid build number: {build_part} in '{filename}'"
+            )
+        build = cast(BuildTag, (int(build_match.group(1)), build_match.group(2)))
+    else:
+        build = ()
+    tags = parse_tag(parts[-1])
+    return (name, version, build, tags)
+
+
+def parse_sdist_filename(filename: str) -> Tuple[NormalizedName, Version]:
+    if filename.endswith(".tar.gz"):
+        file_stem = filename[: -len(".tar.gz")]
+    elif filename.endswith(".zip"):
+        file_stem = filename[: -len(".zip")]
+    else:
+        raise InvalidSdistFilename(
+            f"Invalid sdist filename (extension must be '.tar.gz' or '.zip'):"
+            f" {filename}"
+        )
+
+    # We are requiring a PEP 440 version, which cannot contain dashes,
+    # so we split on the last dash.
+    name_part, sep, version_part = file_stem.rpartition("-")
+    if not sep:
+        raise InvalidSdistFilename(f"Invalid sdist filename: {filename}")
+
+    name = canonicalize_name(name_part)
+    version = Version(version_part)
+    return (name, version)
diff --git a/third_party/python/setuptools/pkg_resources/_vendor/packaging/version.py b/third_party/python/setuptools/pkg_resources/_vendor/packaging/version.py
new file mode 100644
index 0000000000..b30e8cbf84
--- /dev/null
+++ b/third_party/python/setuptools/pkg_resources/_vendor/packaging/version.py
@@ -0,0 +1,564 @@
+# This file is dual licensed under the terms of the Apache License, Version
+# 2.0, and the BSD License. See the LICENSE file in the root of this repository
+# for complete details.
+"""
+.. testsetup::
+
+    from packaging.version import parse, Version
+"""
+
+import collections
+import itertools
+import re
+from typing import Any, Callable, Optional, SupportsInt, Tuple, Union
+
+from ._structures import Infinity, InfinityType, NegativeInfinity, NegativeInfinityType
+
+__all__ = ["VERSION_PATTERN", "parse", "Version", "InvalidVersion"]
+
+InfiniteTypes = Union[InfinityType, NegativeInfinityType]
+PrePostDevType = Union[InfiniteTypes, Tuple[str, int]]
+SubLocalType = Union[InfiniteTypes, int, str]
+LocalType = Union[
+    NegativeInfinityType,
+    Tuple[
+        Union[
+            SubLocalType,
+            Tuple[SubLocalType, str],
+            Tuple[NegativeInfinityType, SubLocalType],
+        ],
+        ...,
+    ],
+]
+CmpKey = Tuple[
+    int, Tuple[int, ...], PrePostDevType, PrePostDevType, PrePostDevType, LocalType
+]
+VersionComparisonMethod = Callable[[CmpKey, CmpKey], bool]
+
+_Version = collections.namedtuple(
+    "_Version", ["epoch", "release", "dev", "pre", "post", "local"]
+)
+
+
+def parse(version: str) -> "Version":
+    """Parse the given version string.
+
+    >>> parse('1.0.dev1')
+    <Version('1.0.dev1')>
+
+    :param version: The version string to parse.
+    :raises InvalidVersion: When the version string is not a valid version.
+    """
+    return Version(version)
+
+
+class InvalidVersion(ValueError):
+    """Raised when a version string is not a valid version.
+
+    >>> Version("invalid")
+    Traceback (most recent call last):
+        ...
+    packaging.version.InvalidVersion: Invalid version: 'invalid'
+    """
+
+
+class _BaseVersion:
+    _key: Tuple[Any, ...]
+
+    def __hash__(self) -> int:
+        return hash(self._key)
+
+    # Please keep the duplicated `isinstance` check
+    # in the six comparisons hereunder
+    # unless you find a way to avoid adding overhead function calls.
+    def __lt__(self, other: "_BaseVersion") -> bool:
+        if not isinstance(other, _BaseVersion):
+            return NotImplemented
+
+        return self._key < other._key
+
+    def __le__(self, other: "_BaseVersion") -> bool:
+        if not isinstance(other, _BaseVersion):
+            return NotImplemented
+
+        return self._key <= other._key
+
+    def __eq__(self, other: object) -> bool:
+        if not isinstance(other, _BaseVersion):
+            return NotImplemented
+
+        return self._key == other._key
+
+    def __ge__(self, other: "_BaseVersion") -> bool:
+        if not isinstance(other, _BaseVersion):
+            return NotImplemented
+
+        return self._key >= other._key
+
+    def __gt__(self, other: "_BaseVersion") -> bool:
+        if not isinstance(other, _BaseVersion):
+            return NotImplemented
+
+        return self._key > other._key
+
+    def __ne__(self, other: object) -> bool:
+        if not isinstance(other, _BaseVersion):
+            return NotImplemented
+
+        return self._key != other._key
+
+
+# Deliberately not anchored to the start and end of the string, to make it
+# easier for 3rd party code to reuse
+_VERSION_PATTERN = r"""
+    v?
+    (?:
+        (?:(?P<epoch>[0-9]+)!)?                           # epoch
+        (?P<release>[0-9]+(?:\.[0-9]+)*)                  # release segment
+        (?P<pre>                                          # pre-release
+            [-_\.]?
+            (?P<pre_l>(a|b|c|rc|alpha|beta|pre|preview))
+            [-_\.]?
+            (?P<pre_n>[0-9]+)?
+        )?
+        (?P<post>                                         # post release
+            (?:-(?P<post_n1>[0-9]+))
+            |
+            (?:
+                [-_\.]?
+                (?P<post_l>post|rev|r)
+                [-_\.]?
+                (?P<post_n2>[0-9]+)?
+            )
+        )?
+        (?P<dev>                                          # dev release
+            [-_\.]?
+            (?P<dev_l>dev)
+            [-_\.]?
+            (?P<dev_n>[0-9]+)?
+        )?
+    )
+    (?:\+(?P<local>[a-z0-9]+(?:[-_\.][a-z0-9]+)*))?       # local version
+"""
+
+VERSION_PATTERN = _VERSION_PATTERN
+"""
+A string containing the regular expression used to match a valid version.
+
+The pattern is not anchored at either end, and is intended for embedding in larger
+expressions (for example, matching a version number as part of a file name). The
+regular expression should be compiled with the ``re.VERBOSE`` and ``re.IGNORECASE``
+flags set.
+
+:meta hide-value:
+"""
+
+
+class Version(_BaseVersion):
+    """This class abstracts handling of a project's versions.
+
+    A :class:`Version` instance is comparison aware and can be compared and
+    sorted using the standard Python interfaces.
+
+    >>> v1 = Version("1.0a5")
+    >>> v2 = Version("1.0")
+    >>> v1
+    <Version('1.0a5')>
+    >>> v2
+    <Version('1.0')>
+    >>> v1 < v2
+    True
+    >>> v1 == v2
+    False
+    >>> v1 > v2
+    False
+    >>> v1 >= v2
+    False
+    >>> v1 <= v2
+    True
+    """
+
+    _regex = re.compile(r"^\s*" + VERSION_PATTERN + r"\s*$", re.VERBOSE | re.IGNORECASE)
+    _key: CmpKey
+
+    def __init__(self, version: str) -> None:
+        """Initialize a Version object.
+
+        :param version:
+            The string representation of a version which will be parsed and normalized
+            before use.
+        :raises InvalidVersion:
+            If the ``version`` does not conform to PEP 440 in any way then this
+            exception will be raised.
+        """
+
+        # Validate the version and parse it into pieces
+        match = self._regex.search(version)
+        if not match:
+            raise InvalidVersion(f"Invalid version: '{version}'")
+
+        # Store the parsed out pieces of the version
+        self._version = _Version(
+            epoch=int(match.group("epoch")) if match.group("epoch") else 0,
+            release=tuple(int(i) for i in match.group("release").split(".")),
+            pre=_parse_letter_version(match.group("pre_l"), match.group("pre_n")),
+            post=_parse_letter_version(
+                match.group("post_l"), match.group("post_n1") or match.group("post_n2")
+            ),
+            dev=_parse_letter_version(match.group("dev_l"), match.group("dev_n")),
+            local=_parse_local_version(match.group("local")),
+        )
+
+        # Generate a key which will be used for sorting
+        self._key = _cmpkey(
+            self._version.epoch,
+            self._version.release,
+            self._version.pre,
+            self._version.post,
+            self._version.dev,
+            self._version.local,
+        )
+
+    def __repr__(self) -> str:
+        """A representation of the Version that shows all internal state.
+
+        >>> Version('1.0.0')
+        <Version('1.0.0')>
+        """
+        return f"<Version('{self}')>"
+
+    def __str__(self) -> str:
+        """A string representation of the version that can be rounded-tripped.
+
+        >>> str(Version("1.0a5"))
+        '1.0a5'
+        """
+        parts = []
+
+        # Epoch
+        if self.epoch != 0:
+            parts.append(f"{self.epoch}!")
+
+        # Release segment
+        parts.append(".".join(str(x) for x in self.release))
+
+        # Pre-release
+        if self.pre is not None:
+            parts.append("".join(str(x) for x in self.pre))
+
+        # Post-release
+        if self.post is not None:
+            parts.append(f".post{self.post}")
+
+        # Development release
+        if self.dev is not None:
+            parts.append(f".dev{self.dev}")
+
+        # Local version segment
+        if self.local is not None:
+            parts.append(f"+{self.local}")
+
+        return "".join(parts)
+
+    @property
+    def epoch(self) -> int:
+        """The epoch of the version.
+
+        >>> Version("2.0.0").epoch
+        0
+        >>> Version("1!2.0.0").epoch
+        1
+        """
+        _epoch: int = self._version.epoch
+        return _epoch
+
+    @property
+    def release(self) -> Tuple[int, ...]:
+        """The components of the "release" segment of the version.
+
+        >>> Version("1.2.3").release
+        (1, 2, 3)
+        >>> Version("2.0.0").release
+        (2, 0, 0)
+        >>> Version("1!2.0.0.post0").release
+        (2, 0, 0)
+
+        Includes trailing zeroes but not the epoch or any pre-release / development /
+        post-release suffixes.
+        """
+        _release: Tuple[int, ...] = self._version.release
+        return _release
+
+    @property
+    def pre(self) -> Optional[Tuple[str, int]]:
+        """The pre-release segment of the version.
+
+        >>> print(Version("1.2.3").pre)
+        None
+        >>> Version("1.2.3a1").pre
+        ('a', 1)
+        >>> Version("1.2.3b1").pre
+        ('b', 1)
+        >>> Version("1.2.3rc1").pre
+        ('rc', 1)
+        """
+        _pre: Optional[Tuple[str, int]] = self._version.pre
+        return _pre
+
+    @property
+    def post(self) -> Optional[int]:
+        """The post-release number of the version.
+
+        >>> print(Version("1.2.3").post)
+        None
+        >>> Version("1.2.3.post1").post
+        1
+        """
+        return self._version.post[1] if self._version.post else None
+
+    @property
+    def dev(self) -> Optional[int]:
+        """The development number of the version.
+
+        >>> print(Version("1.2.3").dev)
+        None
+        >>> Version("1.2.3.dev1").dev
+        1
+        """
+        return self._version.dev[1] if self._version.dev else None
+
+    @property
+    def local(self) -> Optional[str]:
+        """The local version segment of the version.
+
+        >>> print(Version("1.2.3").local)
+        None
+        >>> Version("1.2.3+abc").local
+        'abc'
+        """
+        if self._version.local:
+            return ".".join(str(x) for x in self._version.local)
+        else:
+            return None
+
+    @property
+    def public(self) -> str:
+        """The public portion of the version.
+
+        >>> Version("1.2.3").public
+        '1.2.3'
+        >>> Version("1.2.3+abc").public
+        '1.2.3'
+        >>> Version("1.2.3+abc.dev1").public
+        '1.2.3'
+        """
+        return str(self).split("+", 1)[0]
+
+    @property
+    def base_version(self) -> str:
+        """The "base version" of the version.
+
+        >>> Version("1.2.3").base_version
+        '1.2.3'
+        >>> Version("1.2.3+abc").base_version
+        '1.2.3'
+        >>> Version("1!1.2.3+abc.dev1").base_version
+        '1!1.2.3'
+
+        The "base version" is the public version of the project without any pre or post
+        release markers.
+        """
+        parts = []
+
+        # Epoch
+        if self.epoch != 0:
+            parts.append(f"{self.epoch}!")
+
+        # Release segment
+        parts.append(".".join(str(x) for x in self.release))
+
+        return "".join(parts)
+
+    @property
+    def is_prerelease(self) -> bool:
+        """Whether this version is a pre-release.
+
+        >>> Version("1.2.3").is_prerelease
+        False
+        >>> Version("1.2.3a1").is_prerelease
+        True
+        >>> Version("1.2.3b1").is_prerelease
+        True
+        >>> Version("1.2.3rc1").is_prerelease
+        True
+        >>> Version("1.2.3dev1").is_prerelease
+        True
+        """
+        return self.dev is not None or self.pre is not None
+
+    @property
+    def is_postrelease(self) -> bool:
+        """Whether this version is a post-release.
+
+        >>> Version("1.2.3").is_postrelease
+        False
+        >>> Version("1.2.3.post1").is_postrelease
+        True
+        """
+        return self.post is not None
+
+    @property
+    def is_devrelease(self) -> bool:
+        """Whether this version is a development release.
+
+        >>> Version("1.2.3").is_devrelease
+        False
+        >>> Version("1.2.3.dev1").is_devrelease
+        True
+        """
+        return self.dev is not None
+
+    @property
+    def major(self) -> int:
+        """The first item of :attr:`release` or ``0`` if unavailable.
+
+        >>> Version("1.2.3").major
+        1
+        """
+        return self.release[0] if len(self.release) >= 1 else 0
+
+    @property
+    def minor(self) -> int:
+        """The second item of :attr:`release` or ``0`` if unavailable.
+
+        >>> Version("1.2.3").minor
+        2
+        >>> Version("1").minor
+        0
+        """
+        return self.release[1] if len(self.release) >= 2 else 0
+
+    @property
+    def micro(self) -> int:
+        """The third item of :attr:`release` or ``0`` if unavailable.
+
+        >>> Version("1.2.3").micro
+        3
+        >>> Version("1").micro
+        0
+        """
+        return self.release[2] if len(self.release) >= 3 else 0
+
+
+def _parse_letter_version(
+    letter: str, number: Union[str, bytes, SupportsInt]
+) -> Optional[Tuple[str, int]]:
+
+    if letter:
+        # We consider there to be an implicit 0 in a pre-release if there is
+        # not a numeral associated with it.
+        if number is None:
+            number = 0
+
+        # We normalize any letters to their lower case form
+        letter = letter.lower()
+
+        # We consider some words to be alternate spellings of other words and
+        # in those cases we want to normalize the spellings to our preferred
+        # spelling.
+        if letter == "alpha":
+            letter = "a"
+        elif letter == "beta":
+            letter = "b"
+        elif letter in ["c", "pre", "preview"]:
+            letter = "rc"
+        elif letter in ["rev", "r"]:
+            letter = "post"
+
+        return letter, int(number)
+    if not letter and number:
+        # We assume if we are given a number, but we are not given a letter
+        # then this is using the implicit post release syntax (e.g. 1.0-1)
+        letter = "post"
+
+        return letter, int(number)
+
+    return None
+
+
+_local_version_separators = re.compile(r"[\._-]")
+
+
+def _parse_local_version(local: str) -> Optional[LocalType]:
+    """
+    Takes a string like abc.1.twelve and turns it into ("abc", 1, "twelve").
+    """
+    if local is not None:
+        return tuple(
+            part.lower() if not part.isdigit() else int(part)
+            for part in _local_version_separators.split(local)
+        )
+    return None
+
+
+def _cmpkey(
+    epoch: int,
+    release: Tuple[int, ...],
+    pre: Optional[Tuple[str, int]],
+    post: Optional[Tuple[str, int]],
+    dev: Optional[Tuple[str, int]],
+    local: Optional[Tuple[SubLocalType]],
+) -> CmpKey:
+
+    # When we compare a release version, we want to compare it with all of the
+    # trailing zeros removed. So we'll use a reverse the list, drop all the now
+    # leading zeros until we come to something non zero, then take the rest
+    # re-reverse it back into the correct order and make it a tuple and use
+    # that for our sorting key.
+    _release = tuple(
+        reversed(list(itertools.dropwhile(lambda x: x == 0, reversed(release))))
+    )
+
+    # We need to "trick" the sorting algorithm to put 1.0.dev0 before 1.0a0.
+    # We'll do this by abusing the pre segment, but we _only_ want to do this
+    # if there is not a pre or a post segment. If we have one of those then
+    # the normal sorting rules will handle this case correctly.
+    if pre is None and post is None and dev is not None:
+        _pre: PrePostDevType = NegativeInfinity
+    # Versions without a pre-release (except as noted above) should sort after
+    # those with one.
+    elif pre is None:
+        _pre = Infinity
+    else:
+        _pre = pre
+
+    # Versions without a post segment should sort before those with one.
+    if post is None:
+        _post: PrePostDevType = NegativeInfinity
+
+    else:
+        _post = post
+
+    # Versions without a development segment should sort after those with one.
+    if dev is None:
+        _dev: PrePostDevType = Infinity
+
+    else:
+        _dev = dev
+
+    if local is None:
+        # Versions without a local segment should sort before those with one.
+        _local: LocalType = NegativeInfinity
+    else:
+        # Versions with a local segment need that segment parsed to implement
+        # the sorting rules in PEP440.
+        # - Alpha numeric segments sort before numeric segments
+        # - Alpha numeric segments sort lexicographically
+        # - Numeric segments sort numerically
+        # - Shorter versions sort before longer versions when the prefixes
+        #   match exactly
+        _local = tuple(
+            (i, "") if isinstance(i, int) else (NegativeInfinity, i) for i in local
+        )
+
+    return epoch, _release, _pre, _post, _dev, _local
diff --git a/third_party/python/setuptools/pkg_resources/_vendor/platformdirs/__init__.py b/third_party/python/setuptools/pkg_resources/_vendor/platformdirs/__init__.py
new file mode 100644
index 0000000000..aef2821b83
--- /dev/null
+++ b/third_party/python/setuptools/pkg_resources/_vendor/platformdirs/__init__.py
@@ -0,0 +1,342 @@
+"""
+Utilities for determining application-specific dirs. See <https://github.com/platformdirs/platformdirs> for details and
+usage.
+"""
+from __future__ import annotations
+
+import os
+import sys
+from pathlib import Path
+
+if sys.version_info >= (3, 8):  # pragma: no cover (py38+)
+    from typing import Literal
+else:  # pragma: no cover (py38+)
+    from ..typing_extensions import Literal
+
+from .api import PlatformDirsABC
+from .version import __version__
+from .version import __version_tuple__ as __version_info__
+
+
+def _set_platform_dir_class() -> type[PlatformDirsABC]:
+    if sys.platform == "win32":
+        from .windows import Windows as Result
+    elif sys.platform == "darwin":
+        from .macos import MacOS as Result
+    else:
+        from .unix import Unix as Result
+
+    if os.getenv("ANDROID_DATA") == "/data" and os.getenv("ANDROID_ROOT") == "/system":
+
+        if os.getenv("SHELL") or os.getenv("PREFIX"):
+            return Result
+
+        from .android import _android_folder
+
+        if _android_folder() is not None:
+            from .android import Android
+
+            return Android  # return to avoid redefinition of result
+
+    return Result
+
+
+PlatformDirs = _set_platform_dir_class()  #: Currently active platform
+AppDirs = PlatformDirs  #: Backwards compatibility with appdirs
+
+
+def user_data_dir(
+    appname: str | None = None,
+    appauthor: str | None | Literal[False] = None,
+    version: str | None = None,
+    roaming: bool = False,
+) -> str:
+    """
+    :param appname: See `appname <platformdirs.api.PlatformDirsABC.appname>`.
+    :param appauthor: See `appauthor <platformdirs.api.PlatformDirsABC.appauthor>`.
+    :param version: See `version <platformdirs.api.PlatformDirsABC.version>`.
+    :param roaming: See `roaming <platformdirs.api.PlatformDirsABC.version>`.
+    :returns: data directory tied to the user
+    """
+    return PlatformDirs(appname=appname, appauthor=appauthor, version=version, roaming=roaming).user_data_dir
+
+
+def site_data_dir(
+    appname: str | None = None,
+    appauthor: str | None | Literal[False] = None,
+    version: str | None = None,
+    multipath: bool = False,
+) -> str:
+    """
+    :param appname: See `appname <platformdirs.api.PlatformDirsABC.appname>`.
+    :param appauthor: See `appauthor <platformdirs.api.PlatformDirsABC.appauthor>`.
+    :param version: See `version <platformdirs.api.PlatformDirsABC.version>`.
+    :param multipath: See `roaming <platformdirs.api.PlatformDirsABC.multipath>`.
+    :returns: data directory shared by users
+    """
+    return PlatformDirs(appname=appname, appauthor=appauthor, version=version, multipath=multipath).site_data_dir
+
+
+def user_config_dir(
+    appname: str | None = None,
+    appauthor: str | None | Literal[False] = None,
+    version: str | None = None,
+    roaming: bool = False,
+) -> str:
+    """
+    :param appname: See `appname <platformdirs.api.PlatformDirsABC.appname>`.
+    :param appauthor: See `appauthor <platformdirs.api.PlatformDirsABC.appauthor>`.
+    :param version: See `version <platformdirs.api.PlatformDirsABC.version>`.
+    :param roaming: See `roaming <platformdirs.api.PlatformDirsABC.version>`.
+    :returns: config directory tied to the user
+    """
+    return PlatformDirs(appname=appname, appauthor=appauthor, version=version, roaming=roaming).user_config_dir
+
+
+def site_config_dir(
+    appname: str | None = None,
+    appauthor: str | None | Literal[False] = None,
+    version: str | None = None,
+    multipath: bool = False,
+) -> str:
+    """
+    :param appname: See `appname <platformdirs.api.PlatformDirsABC.appname>`.
+    :param appauthor: See `appauthor <platformdirs.api.PlatformDirsABC.appauthor>`.
+    :param version: See `version <platformdirs.api.PlatformDirsABC.version>`.
+    :param multipath: See `roaming <platformdirs.api.PlatformDirsABC.multipath>`.
+    :returns: config directory shared by the users
+    """
+    return PlatformDirs(appname=appname, appauthor=appauthor, version=version, multipath=multipath).site_config_dir
+
+
+def user_cache_dir(
+    appname: str | None = None,
+    appauthor: str | None | Literal[False] = None,
+    version: str | None = None,
+    opinion: bool = True,
+) -> str:
+    """
+    :param appname: See `appname <platformdirs.api.PlatformDirsABC.appname>`.
+    :param appauthor: See `appauthor <platformdirs.api.PlatformDirsABC.appauthor>`.
+    :param version: See `version <platformdirs.api.PlatformDirsABC.version>`.
+    :param opinion: See `roaming <platformdirs.api.PlatformDirsABC.opinion>`.
+    :returns: cache directory tied to the user
+    """
+    return PlatformDirs(appname=appname, appauthor=appauthor, version=version, opinion=opinion).user_cache_dir
+
+
+def user_state_dir(
+    appname: str | None = None,
+    appauthor: str | None | Literal[False] = None,
+    version: str | None = None,
+    roaming: bool = False,
+) -> str:
+    """
+    :param appname: See `appname <platformdirs.api.PlatformDirsABC.appname>`.
+    :param appauthor: See `appauthor <platformdirs.api.PlatformDirsABC.appauthor>`.
+    :param version: See `version <platformdirs.api.PlatformDirsABC.version>`.
+    :param roaming: See `roaming <platformdirs.api.PlatformDirsABC.version>`.
+    :returns: state directory tied to the user
+    """
+    return PlatformDirs(appname=appname, appauthor=appauthor, version=version, roaming=roaming).user_state_dir
+
+
+def user_log_dir(
+    appname: str | None = None,
+    appauthor: str | None | Literal[False] = None,
+    version: str | None = None,
+    opinion: bool = True,
+) -> str:
+    """
+    :param appname: See `appname <platformdirs.api.PlatformDirsABC.appname>`.
+    :param appauthor: See `appauthor <platformdirs.api.PlatformDirsABC.appauthor>`.
+    :param version: See `version <platformdirs.api.PlatformDirsABC.version>`.
+    :param opinion: See `roaming <platformdirs.api.PlatformDirsABC.opinion>`.
+    :returns: log directory tied to the user
+    """
+    return PlatformDirs(appname=appname, appauthor=appauthor, version=version, opinion=opinion).user_log_dir
+
+
+def user_documents_dir() -> str:
+    """
+    :returns: documents directory tied to the user
+    """
+    return PlatformDirs().user_documents_dir
+
+
+def user_runtime_dir(
+    appname: str | None = None,
+    appauthor: str | None | Literal[False] = None,
+    version: str | None = None,
+    opinion: bool = True,
+) -> str:
+    """
+    :param appname: See `appname <platformdirs.api.PlatformDirsABC.appname>`.
+    :param appauthor: See `appauthor <platformdirs.api.PlatformDirsABC.appauthor>`.
+    :param version: See `version <platformdirs.api.PlatformDirsABC.version>`.
+    :param opinion: See `opinion <platformdirs.api.PlatformDirsABC.opinion>`.
+    :returns: runtime directory tied to the user
+    """
+    return PlatformDirs(appname=appname, appauthor=appauthor, version=version, opinion=opinion).user_runtime_dir
+
+
+def user_data_path(
+    appname: str | None = None,
+    appauthor: str | None | Literal[False] = None,
+    version: str | None = None,
+    roaming: bool = False,
+) -> Path:
+    """
+    :param appname: See `appname <platformdirs.api.PlatformDirsABC.appname>`.
+    :param appauthor: See `appauthor <platformdirs.api.PlatformDirsABC.appauthor>`.
+    :param version: See `version <platformdirs.api.PlatformDirsABC.version>`.
+    :param roaming: See `roaming <platformdirs.api.PlatformDirsABC.version>`.
+    :returns: data path tied to the user
+    """
+    return PlatformDirs(appname=appname, appauthor=appauthor, version=version, roaming=roaming).user_data_path
+
+
+def site_data_path(
+    appname: str | None = None,
+    appauthor: str | None | Literal[False] = None,
+    version: str | None = None,
+    multipath: bool = False,
+) -> Path:
+    """
+    :param appname: See `appname <platformdirs.api.PlatformDirsABC.appname>`.
+    :param appauthor: See `appauthor <platformdirs.api.PlatformDirsABC.appauthor>`.
+    :param version: See `version <platformdirs.api.PlatformDirsABC.version>`.
+    :param multipath: See `multipath <platformdirs.api.PlatformDirsABC.multipath>`.
+    :returns: data path shared by users
+    """
+    return PlatformDirs(appname=appname, appauthor=appauthor, version=version, multipath=multipath).site_data_path
+
+
+def user_config_path(
+    appname: str | None = None,
+    appauthor: str | None | Literal[False] = None,
+    version: str | None = None,
+    roaming: bool = False,
+) -> Path:
+    """
+    :param appname: See `appname <platformdirs.api.PlatformDirsABC.appname>`.
+    :param appauthor: See `appauthor <platformdirs.api.PlatformDirsABC.appauthor>`.
+    :param version: See `version <platformdirs.api.PlatformDirsABC.version>`.
+    :param roaming: See `roaming <platformdirs.api.PlatformDirsABC.version>`.
+    :returns: config path tied to the user
+    """
+    return PlatformDirs(appname=appname, appauthor=appauthor, version=version, roaming=roaming).user_config_path
+
+
+def site_config_path(
+    appname: str | None = None,
+    appauthor: str | None | Literal[False] = None,
+    version: str | None = None,
+    multipath: bool = False,
+) -> Path:
+    """
+    :param appname: See `appname <platformdirs.api.PlatformDirsABC.appname>`.
+    :param appauthor: See `appauthor <platformdirs.api.PlatformDirsABC.appauthor>`.
+    :param version: See `version <platformdirs.api.PlatformDirsABC.version>`.
+    :param multipath: See `roaming <platformdirs.api.PlatformDirsABC.multipath>`.
+    :returns: config path shared by the users
+    """
+    return PlatformDirs(appname=appname, appauthor=appauthor, version=version, multipath=multipath).site_config_path
+
+
+def user_cache_path(
+    appname: str | None = None,
+    appauthor: str | None | Literal[False] = None,
+    version: str | None = None,
+    opinion: bool = True,
+) -> Path:
+    """
+    :param appname: See `appname <platformdirs.api.PlatformDirsABC.appname>`.
+    :param appauthor: See `appauthor <platformdirs.api.PlatformDirsABC.appauthor>`.
+    :param version: See `version <platformdirs.api.PlatformDirsABC.version>`.
+    :param opinion: See `roaming <platformdirs.api.PlatformDirsABC.opinion>`.
+    :returns: cache path tied to the user
+    """
+    return PlatformDirs(appname=appname, appauthor=appauthor, version=version, opinion=opinion).user_cache_path
+
+
+def user_state_path(
+    appname: str | None = None,
+    appauthor: str | None | Literal[False] = None,
+    version: str | None = None,
+    roaming: bool = False,
+) -> Path:
+    """
+    :param appname: See `appname <platformdirs.api.PlatformDirsABC.appname>`.
+    :param appauthor: See `appauthor <platformdirs.api.PlatformDirsABC.appauthor>`.
+    :param version: See `version <platformdirs.api.PlatformDirsABC.version>`.
+    :param roaming: See `roaming <platformdirs.api.PlatformDirsABC.version>`.
+    :returns: state path tied to the user
+    """
+    return PlatformDirs(appname=appname, appauthor=appauthor, version=version, roaming=roaming).user_state_path
+
+
+def user_log_path(
+    appname: str | None = None,
+    appauthor: str | None | Literal[False] = None,
+    version: str | None = None,
+    opinion: bool = True,
+) -> Path:
+    """
+    :param appname: See `appname <platformdirs.api.PlatformDirsABC.appname>`.
+    :param appauthor: See `appauthor <platformdirs.api.PlatformDirsABC.appauthor>`.
+    :param version: See `version <platformdirs.api.PlatformDirsABC.version>`.
+    :param opinion: See `roaming <platformdirs.api.PlatformDirsABC.opinion>`.
+    :returns: log path tied to the user
+    """
+    return PlatformDirs(appname=appname, appauthor=appauthor, version=version, opinion=opinion).user_log_path
+
+
+def user_documents_path() -> Path:
+    """
+    :returns: documents path tied to the user
+    """
+    return PlatformDirs().user_documents_path
+
+
+def user_runtime_path(
+    appname: str | None = None,
+    appauthor: str | None | Literal[False] = None,
+    version: str | None = None,
+    opinion: bool = True,
+) -> Path:
+    """
+    :param appname: See `appname <platformdirs.api.PlatformDirsABC.appname>`.
+    :param appauthor: See `appauthor <platformdirs.api.PlatformDirsABC.appauthor>`.
+    :param version: See `version <platformdirs.api.PlatformDirsABC.version>`.
+    :param opinion: See `opinion <platformdirs.api.PlatformDirsABC.opinion>`.
+    :returns: runtime path tied to the user
+    """
+    return PlatformDirs(appname=appname, appauthor=appauthor, version=version, opinion=opinion).user_runtime_path
+
+
+__all__ = [
+    "__version__",
+    "__version_info__",
+    "PlatformDirs",
+    "AppDirs",
+    "PlatformDirsABC",
+    "user_data_dir",
+    "user_config_dir",
+    "user_cache_dir",
+    "user_state_dir",
+    "user_log_dir",
+    "user_documents_dir",
+    "user_runtime_dir",
+    "site_data_dir",
+    "site_config_dir",
+    "user_data_path",
+    "user_config_path",
+    "user_cache_path",
+    "user_state_path",
+    "user_log_path",
+    "user_documents_path",
+    "user_runtime_path",
+    "site_data_path",
+    "site_config_path",
+]
diff --git a/third_party/python/setuptools/pkg_resources/_vendor/platformdirs/__main__.py b/third_party/python/setuptools/pkg_resources/_vendor/platformdirs/__main__.py
new file mode 100644
index 0000000000..0fc1edd59c
--- /dev/null
+++ b/third_party/python/setuptools/pkg_resources/_vendor/platformdirs/__main__.py
@@ -0,0 +1,46 @@
+from __future__ import annotations
+
+from platformdirs import PlatformDirs, __version__
+
+PROPS = (
+    "user_data_dir",
+    "user_config_dir",
+    "user_cache_dir",
+    "user_state_dir",
+    "user_log_dir",
+    "user_documents_dir",
+    "user_runtime_dir",
+    "site_data_dir",
+    "site_config_dir",
+)
+
+
+def main() -> None:
+    app_name = "MyApp"
+    app_author = "MyCompany"
+
+    print(f"-- platformdirs {__version__} --")
+
+    print("-- app dirs (with optional 'version')")
+    dirs = PlatformDirs(app_name, app_author, version="1.0")
+    for prop in PROPS:
+        print(f"{prop}: {getattr(dirs, prop)}")
+
+    print("\n-- app dirs (without optional 'version')")
+    dirs = PlatformDirs(app_name, app_author)
+    for prop in PROPS:
+        print(f"{prop}: {getattr(dirs, prop)}")
+
+    print("\n-- app dirs (without optional 'appauthor')")
+    dirs = PlatformDirs(app_name)
+    for prop in PROPS:
+        print(f"{prop}: {getattr(dirs, prop)}")
+
+    print("\n-- app dirs (with disabled 'appauthor')")
+    dirs = PlatformDirs(app_name, appauthor=False)
+    for prop in PROPS:
+        print(f"{prop}: {getattr(dirs, prop)}")
+
+
+if __name__ == "__main__":
+    main()
diff --git a/third_party/python/setuptools/pkg_resources/_vendor/platformdirs/android.py b/third_party/python/setuptools/pkg_resources/_vendor/platformdirs/android.py
new file mode 100644
index 0000000000..eda8093512
--- /dev/null
+++ b/third_party/python/setuptools/pkg_resources/_vendor/platformdirs/android.py
@@ -0,0 +1,120 @@
+from __future__ import annotations
+
+import os
+import re
+import sys
+from functools import lru_cache
+from typing import cast
+
+from .api import PlatformDirsABC
+
+
+class Android(PlatformDirsABC):
+    """
+    Follows the guidance `from here <https://android.stackexchange.com/a/216132>`_. Makes use of the
+    `appname <platformdirs.api.PlatformDirsABC.appname>` and
+    `version <platformdirs.api.PlatformDirsABC.version>`.
+    """
+
+    @property
+    def user_data_dir(self) -> str:
+        """:return: data directory tied to the user, e.g. ``/data/user/<userid>/<packagename>/files/<AppName>``"""
+        return self._append_app_name_and_version(cast(str, _android_folder()), "files")
+
+    @property
+    def site_data_dir(self) -> str:
+        """:return: data directory shared by users, same as `user_data_dir`"""
+        return self.user_data_dir
+
+    @property
+    def user_config_dir(self) -> str:
+        """
+        :return: config directory tied to the user, e.g. ``/data/user/<userid>/<packagename>/shared_prefs/<AppName>``
+        """
+        return self._append_app_name_and_version(cast(str, _android_folder()), "shared_prefs")
+
+    @property
+    def site_config_dir(self) -> str:
+        """:return: config directory shared by the users, same as `user_config_dir`"""
+        return self.user_config_dir
+
+    @property
+    def user_cache_dir(self) -> str:
+        """:return: cache directory tied to the user, e.g. e.g. ``/data/user/<userid>/<packagename>/cache/<AppName>``"""
+        return self._append_app_name_and_version(cast(str, _android_folder()), "cache")
+
+    @property
+    def user_state_dir(self) -> str:
+        """:return: state directory tied to the user, same as `user_data_dir`"""
+        return self.user_data_dir
+
+    @property
+    def user_log_dir(self) -> str:
+        """
+        :return: log directory tied to the user, same as `user_cache_dir` if not opinionated else ``log`` in it,
+          e.g. ``/data/user/<userid>/<packagename>/cache/<AppName>/log``
+        """
+        path = self.user_cache_dir
+        if self.opinion:
+            path = os.path.join(path, "log")
+        return path
+
+    @property
+    def user_documents_dir(self) -> str:
+        """
+        :return: documents directory tied to the user e.g. ``/storage/emulated/0/Documents``
+        """
+        return _android_documents_folder()
+
+    @property
+    def user_runtime_dir(self) -> str:
+        """
+        :return: runtime directory tied to the user, same as `user_cache_dir` if not opinionated else ``tmp`` in it,
+          e.g. ``/data/user/<userid>/<packagename>/cache/<AppName>/tmp``
+        """
+        path = self.user_cache_dir
+        if self.opinion:
+            path = os.path.join(path, "tmp")
+        return path
+
+
+@lru_cache(maxsize=1)
+def _android_folder() -> str | None:
+    """:return: base folder for the Android OS or None if cannot be found"""
+    try:
+        # First try to get path to android app via pyjnius
+        from jnius import autoclass
+
+        Context = autoclass("android.content.Context")  # noqa: N806
+        result: str | None = Context.getFilesDir().getParentFile().getAbsolutePath()
+    except Exception:
+        # if fails find an android folder looking path on the sys.path
+        pattern = re.compile(r"/data/(data|user/\d+)/(.+)/files")
+        for path in sys.path:
+            if pattern.match(path):
+                result = path.split("/files")[0]
+                break
+        else:
+            result = None
+    return result
+
+
+@lru_cache(maxsize=1)
+def _android_documents_folder() -> str:
+    """:return: documents folder for the Android OS"""
+    # Get directories with pyjnius
+    try:
+        from jnius import autoclass
+
+        Context = autoclass("android.content.Context")  # noqa: N806
+        Environment = autoclass("android.os.Environment")  # noqa: N806
+        documents_dir: str = Context.getExternalFilesDir(Environment.DIRECTORY_DOCUMENTS).getAbsolutePath()
+    except Exception:
+        documents_dir = "/storage/emulated/0/Documents"
+
+    return documents_dir
+
+
+__all__ = [
+    "Android",
+]
diff --git a/third_party/python/setuptools/pkg_resources/_vendor/platformdirs/api.py b/third_party/python/setuptools/pkg_resources/_vendor/platformdirs/api.py
new file mode 100644
index 0000000000..6f6e2c2c69
--- /dev/null
+++ b/third_party/python/setuptools/pkg_resources/_vendor/platformdirs/api.py
@@ -0,0 +1,156 @@
+from __future__ import annotations
+
+import os
+import sys
+from abc import ABC, abstractmethod
+from pathlib import Path
+
+if sys.version_info >= (3, 8):  # pragma: no branch
+    from typing import Literal  # pragma: no cover
+
+
+class PlatformDirsABC(ABC):
+    """
+    Abstract base class for platform directories.
+    """
+
+    def __init__(
+        self,
+        appname: str | None = None,
+        appauthor: str | None | Literal[False] = None,
+        version: str | None = None,
+        roaming: bool = False,
+        multipath: bool = False,
+        opinion: bool = True,
+    ):
+        """
+        Create a new platform directory.
+
+        :param appname: See `appname`.
+        :param appauthor: See `appauthor`.
+        :param version: See `version`.
+        :param roaming: See `roaming`.
+        :param multipath: See `multipath`.
+        :param opinion: See `opinion`.
+        """
+        self.appname = appname  #: The name of application.
+        self.appauthor = appauthor
+        """
+        The name of the app author or distributing body for this application. Typically, it is the owning company name.
+        Defaults to `appname`. You may pass ``False`` to disable it.
+        """
+        self.version = version
+        """
+        An optional version path element to append to the path. You might want to use this if you want multiple versions
+        of your app to be able to run independently. If used, this would typically be ``<major>.<minor>``.
+        """
+        self.roaming = roaming
+        """
+        Whether to use the roaming appdata directory on Windows. That means that for users on a Windows network setup
+        for roaming profiles, this user data will be synced on login (see
+        `here <http://technet.microsoft.com/en-us/library/cc766489(WS.10).aspx>`_).
+        """
+        self.multipath = multipath
+        """
+        An optional parameter only applicable to Unix/Linux which indicates that the entire list of data dirs should be
+        returned. By default, the first item would only be returned.
+        """
+        self.opinion = opinion  #: A flag to indicating to use opinionated values.
+
+    def _append_app_name_and_version(self, *base: str) -> str:
+        params = list(base[1:])
+        if self.appname:
+            params.append(self.appname)
+            if self.version:
+                params.append(self.version)
+        return os.path.join(base[0], *params)
+
+    @property
+    @abstractmethod
+    def user_data_dir(self) -> str:
+        """:return: data directory tied to the user"""
+
+    @property
+    @abstractmethod
+    def site_data_dir(self) -> str:
+        """:return: data directory shared by users"""
+
+    @property
+    @abstractmethod
+    def user_config_dir(self) -> str:
+        """:return: config directory tied to the user"""
+
+    @property
+    @abstractmethod
+    def site_config_dir(self) -> str:
+        """:return: config directory shared by the users"""
+
+    @property
+    @abstractmethod
+    def user_cache_dir(self) -> str:
+        """:return: cache directory tied to the user"""
+
+    @property
+    @abstractmethod
+    def user_state_dir(self) -> str:
+        """:return: state directory tied to the user"""
+
+    @property
+    @abstractmethod
+    def user_log_dir(self) -> str:
+        """:return: log directory tied to the user"""
+
+    @property
+    @abstractmethod
+    def user_documents_dir(self) -> str:
+        """:return: documents directory tied to the user"""
+
+    @property
+    @abstractmethod
+    def user_runtime_dir(self) -> str:
+        """:return: runtime directory tied to the user"""
+
+    @property
+    def user_data_path(self) -> Path:
+        """:return: data path tied to the user"""
+        return Path(self.user_data_dir)
+
+    @property
+    def site_data_path(self) -> Path:
+        """:return: data path shared by users"""
+        return Path(self.site_data_dir)
+
+    @property
+    def user_config_path(self) -> Path:
+        """:return: config path tied to the user"""
+        return Path(self.user_config_dir)
+
+    @property
+    def site_config_path(self) -> Path:
+        """:return: config path shared by the users"""
+        return Path(self.site_config_dir)
+
+    @property
+    def user_cache_path(self) -> Path:
+        """:return: cache path tied to the user"""
+        return Path(self.user_cache_dir)
+
+    @property
+    def user_state_path(self) -> Path:
+        """:return: state path tied to the user"""
+        return Path(self.user_state_dir)
+
+    @property
+    def user_log_path(self) -> Path:
+        """:return: log path tied to the user"""
+        return Path(self.user_log_dir)
+
+    @property
+    def user_documents_path(self) -> Path:
+        """:return: documents path tied to the user"""
+        return Path(self.user_documents_dir)
+
+    @property
+    def user_runtime_path(self) -> Path:
+        """:return: runtime path tied to the user"""
+        return Path(self.user_runtime_dir)
diff --git a/third_party/python/setuptools/pkg_resources/_vendor/platformdirs/macos.py b/third_party/python/setuptools/pkg_resources/_vendor/platformdirs/macos.py
new file mode 100644
index 0000000000..a01337c776
--- /dev/null
+++ b/third_party/python/setuptools/pkg_resources/_vendor/platformdirs/macos.py
@@ -0,0 +1,64 @@
+from __future__ import annotations
+
+import os
+
+from .api import PlatformDirsABC
+
+
+class MacOS(PlatformDirsABC):
+    """
+    Platform directories for the macOS operating system. Follows the guidance from `Apple documentation
+    <https://developer.apple.com/library/archive/documentation/FileManagement/Conceptual/FileSystemProgrammingGuide/MacOSXDirectories/MacOSXDirectories.html>`_.
+    Makes use of the `appname <platformdirs.api.PlatformDirsABC.appname>` and
+    `version <platformdirs.api.PlatformDirsABC.version>`.
+    """
+
+    @property
+    def user_data_dir(self) -> str:
+        """:return: data directory tied to the user, e.g. ``~/Library/Application Support/$appname/$version``"""
+        return self._append_app_name_and_version(os.path.expanduser("~/Library/Application Support/"))
+
+    @property
+    def site_data_dir(self) -> str:
+        """:return: data directory shared by users, e.g. ``/Library/Application Support/$appname/$version``"""
+        return self._append_app_name_and_version("/Library/Application Support")
+
+    @property
+    def user_config_dir(self) -> str:
+        """:return: config directory tied to the user, e.g. ``~/Library/Preferences/$appname/$version``"""
+        return self._append_app_name_and_version(os.path.expanduser("~/Library/Preferences/"))
+
+    @property
+    def site_config_dir(self) -> str:
+        """:return: config directory shared by the users, e.g. ``/Library/Preferences/$appname``"""
+        return self._append_app_name_and_version("/Library/Preferences")
+
+    @property
+    def user_cache_dir(self) -> str:
+        """:return: cache directory tied to the user, e.g. ``~/Library/Caches/$appname/$version``"""
+        return self._append_app_name_and_version(os.path.expanduser("~/Library/Caches"))
+
+    @property
+    def user_state_dir(self) -> str:
+        """:return: state directory tied to the user, same as `user_data_dir`"""
+        return self.user_data_dir
+
+    @property
+    def user_log_dir(self) -> str:
+        """:return: log directory tied to the user, e.g. ``~/Library/Logs/$appname/$version``"""
+        return self._append_app_name_and_version(os.path.expanduser("~/Library/Logs"))
+
+    @property
+    def user_documents_dir(self) -> str:
+        """:return: documents directory tied to the user, e.g. ``~/Documents``"""
+        return os.path.expanduser("~/Documents")
+
+    @property
+    def user_runtime_dir(self) -> str:
+        """:return: runtime directory tied to the user, e.g. ``~/Library/Caches/TemporaryItems/$appname/$version``"""
+        return self._append_app_name_and_version(os.path.expanduser("~/Library/Caches/TemporaryItems"))
+
+
+__all__ = [
+    "MacOS",
+]
diff --git a/third_party/python/setuptools/pkg_resources/_vendor/platformdirs/unix.py b/third_party/python/setuptools/pkg_resources/_vendor/platformdirs/unix.py
new file mode 100644
index 0000000000..9aca5a0305
--- /dev/null
+++ b/third_party/python/setuptools/pkg_resources/_vendor/platformdirs/unix.py
@@ -0,0 +1,181 @@
+from __future__ import annotations
+
+import os
+import sys
+from configparser import ConfigParser
+from pathlib import Path
+
+from .api import PlatformDirsABC
+
+if sys.platform.startswith("linux"):  # pragma: no branch # no op check, only to please the type checker
+    from os import getuid
+else:
+
+    def getuid() -> int:
+        raise RuntimeError("should only be used on Linux")
+
+
+class Unix(PlatformDirsABC):
+    """
+    On Unix/Linux, we follow the
+    `XDG Basedir Spec <https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html>`_. The spec allows
+    overriding directories with environment variables. The examples show are the default values, alongside the name of
+    the environment variable that overrides them. Makes use of the
+    `appname <platformdirs.api.PlatformDirsABC.appname>`,
+    `version <platformdirs.api.PlatformDirsABC.version>`,
+    `multipath <platformdirs.api.PlatformDirsABC.multipath>`,
+    `opinion <platformdirs.api.PlatformDirsABC.opinion>`.
+    """
+
+    @property
+    def user_data_dir(self) -> str:
+        """
+        :return: data directory tied to the user, e.g. ``~/.local/share/$appname/$version`` or
+         ``$XDG_DATA_HOME/$appname/$version``
+        """
+        path = os.environ.get("XDG_DATA_HOME", "")
+        if not path.strip():
+            path = os.path.expanduser("~/.local/share")
+        return self._append_app_name_and_version(path)
+
+    @property
+    def site_data_dir(self) -> str:
+        """
+        :return: data directories shared by users (if `multipath <platformdirs.api.PlatformDirsABC.multipath>` is
+         enabled and ``XDG_DATA_DIR`` is set and a multi path the response is also a multi path separated by the OS
+         path separator), e.g. ``/usr/local/share/$appname/$version`` or ``/usr/share/$appname/$version``
+        """
+        # XDG default for $XDG_DATA_DIRS; only first, if multipath is False
+        path = os.environ.get("XDG_DATA_DIRS", "")
+        if not path.strip():
+            path = f"/usr/local/share{os.pathsep}/usr/share"
+        return self._with_multi_path(path)
+
+    def _with_multi_path(self, path: str) -> str:
+        path_list = path.split(os.pathsep)
+        if not self.multipath:
+            path_list = path_list[0:1]
+        path_list = [self._append_app_name_and_version(os.path.expanduser(p)) for p in path_list]
+        return os.pathsep.join(path_list)
+
+    @property
+    def user_config_dir(self) -> str:
+        """
+        :return: config directory tied to the user, e.g. ``~/.config/$appname/$version`` or
+         ``$XDG_CONFIG_HOME/$appname/$version``
+        """
+        path = os.environ.get("XDG_CONFIG_HOME", "")
+        if not path.strip():
+            path = os.path.expanduser("~/.config")
+        return self._append_app_name_and_version(path)
+
+    @property
+    def site_config_dir(self) -> str:
+        """
+        :return: config directories shared by users (if `multipath <platformdirs.api.PlatformDirsABC.multipath>`
+         is enabled and ``XDG_DATA_DIR`` is set and a multi path the response is also a multi path separated by the OS
+         path separator), e.g. ``/etc/xdg/$appname/$version``
+        """
+        # XDG default for $XDG_CONFIG_DIRS only first, if multipath is False
+        path = os.environ.get("XDG_CONFIG_DIRS", "")
+        if not path.strip():
+            path = "/etc/xdg"
+        return self._with_multi_path(path)
+
+    @property
+    def user_cache_dir(self) -> str:
+        """
+        :return: cache directory tied to the user, e.g. ``~/.cache/$appname/$version`` or
+         ``~/$XDG_CACHE_HOME/$appname/$version``
+        """
+        path = os.environ.get("XDG_CACHE_HOME", "")
+        if not path.strip():
+            path = os.path.expanduser("~/.cache")
+        return self._append_app_name_and_version(path)
+
+    @property
+    def user_state_dir(self) -> str:
+        """
+        :return: state directory tied to the user, e.g. ``~/.local/state/$appname/$version`` or
+         ``$XDG_STATE_HOME/$appname/$version``
+        """
+        path = os.environ.get("XDG_STATE_HOME", "")
+        if not path.strip():
+            path = os.path.expanduser("~/.local/state")
+        return self._append_app_name_and_version(path)
+
+    @property
+    def user_log_dir(self) -> str:
+        """
+        :return: log directory tied to the user, same as `user_state_dir` if not opinionated else ``log`` in it
+        """
+        path = self.user_state_dir
+        if self.opinion:
+            path = os.path.join(path, "log")
+        return path
+
+    @property
+    def user_documents_dir(self) -> str:
+        """
+        :return: documents directory tied to the user, e.g. ``~/Documents``
+        """
+        documents_dir = _get_user_dirs_folder("XDG_DOCUMENTS_DIR")
+        if documents_dir is None:
+            documents_dir = os.environ.get("XDG_DOCUMENTS_DIR", "").strip()
+            if not documents_dir:
+                documents_dir = os.path.expanduser("~/Documents")
+
+        return documents_dir
+
+    @property
+    def user_runtime_dir(self) -> str:
+        """
+        :return: runtime directory tied to the user, e.g. ``/run/user/$(id -u)/$appname/$version`` or
+         ``$XDG_RUNTIME_DIR/$appname/$version``
+        """
+        path = os.environ.get("XDG_RUNTIME_DIR", "")
+        if not path.strip():
+            path = f"/run/user/{getuid()}"
+        return self._append_app_name_and_version(path)
+
+    @property
+    def site_data_path(self) -> Path:
+        """:return: data path shared by users. Only return first item, even if ``multipath`` is set to ``True``"""
+        return self._first_item_as_path_if_multipath(self.site_data_dir)
+
+    @property
+    def site_config_path(self) -> Path:
+        """:return: config path shared by the users. Only return first item, even if ``multipath`` is set to ``True``"""
+        return self._first_item_as_path_if_multipath(self.site_config_dir)
+
+    def _first_item_as_path_if_multipath(self, directory: str) -> Path:
+        if self.multipath:
+            # If multipath is True, the first path is returned.
+            directory = directory.split(os.pathsep)[0]
+        return Path(directory)
+
+
+def _get_user_dirs_folder(key: str) -> str | None:
+    """Return directory from user-dirs.dirs config file. See https://freedesktop.org/wiki/Software/xdg-user-dirs/"""
+    user_dirs_config_path = os.path.join(Unix().user_config_dir, "user-dirs.dirs")
+    if os.path.exists(user_dirs_config_path):
+        parser = ConfigParser()
+
+        with open(user_dirs_config_path) as stream:
+            # Add fake section header, so ConfigParser doesn't complain
+            parser.read_string(f"[top]\n{stream.read()}")
+
+        if key not in parser["top"]:
+            return None
+
+        path = parser["top"][key].strip('"')
+        # Handle relative home paths
+        path = path.replace("$HOME", os.path.expanduser("~"))
+        return path
+
+    return None
+
+
+__all__ = [
+    "Unix",
+]
diff --git a/third_party/python/setuptools/pkg_resources/_vendor/platformdirs/version.py b/third_party/python/setuptools/pkg_resources/_vendor/platformdirs/version.py
new file mode 100644
index 0000000000..9f6eb98e8f
--- /dev/null
+++ b/third_party/python/setuptools/pkg_resources/_vendor/platformdirs/version.py
@@ -0,0 +1,4 @@
+# file generated by setuptools_scm
+# don't change, don't track in version control
+__version__ = version = '2.6.2'
+__version_tuple__ = version_tuple = (2, 6, 2)
diff --git a/third_party/python/setuptools/pkg_resources/_vendor/platformdirs/windows.py b/third_party/python/setuptools/pkg_resources/_vendor/platformdirs/windows.py
new file mode 100644
index 0000000000..d5c27b3414
--- /dev/null
+++ b/third_party/python/setuptools/pkg_resources/_vendor/platformdirs/windows.py
@@ -0,0 +1,184 @@
+from __future__ import annotations
+
+import ctypes
+import os
+import sys
+from functools import lru_cache
+from typing import Callable
+
+from .api import PlatformDirsABC
+
+
+class Windows(PlatformDirsABC):
+    """`MSDN on where to store app data files
+    <http://support.microsoft.com/default.aspx?scid=kb;en-us;310294#XSLTH3194121123120121120120>`_.
+    Makes use of the
+    `appname <platformdirs.api.PlatformDirsABC.appname>`,
+    `appauthor <platformdirs.api.PlatformDirsABC.appauthor>`,
+    `version <platformdirs.api.PlatformDirsABC.version>`,
+    `roaming <platformdirs.api.PlatformDirsABC.roaming>`,
+    `opinion <platformdirs.api.PlatformDirsABC.opinion>`."""
+
+    @property
+    def user_data_dir(self) -> str:
+        """
+        :return: data directory tied to the user, e.g.
+         ``%USERPROFILE%\\AppData\\Local\\$appauthor\\$appname`` (not roaming) or
+         ``%USERPROFILE%\\AppData\\Roaming\\$appauthor\\$appname`` (roaming)
+        """
+        const = "CSIDL_APPDATA" if self.roaming else "CSIDL_LOCAL_APPDATA"
+        path = os.path.normpath(get_win_folder(const))
+        return self._append_parts(path)
+
+    def _append_parts(self, path: str, *, opinion_value: str | None = None) -> str:
+        params = []
+        if self.appname:
+            if self.appauthor is not False:
+                author = self.appauthor or self.appname
+                params.append(author)
+            params.append(self.appname)
+            if opinion_value is not None and self.opinion:
+                params.append(opinion_value)
+            if self.version:
+                params.append(self.version)
+        return os.path.join(path, *params)
+
+    @property
+    def site_data_dir(self) -> str:
+        """:return: data directory shared by users, e.g. ``C:\\ProgramData\\$appauthor\\$appname``"""
+        path = os.path.normpath(get_win_folder("CSIDL_COMMON_APPDATA"))
+        return self._append_parts(path)
+
+    @property
+    def user_config_dir(self) -> str:
+        """:return: config directory tied to the user, same as `user_data_dir`"""
+        return self.user_data_dir
+
+    @property
+    def site_config_dir(self) -> str:
+        """:return: config directory shared by the users, same as `site_data_dir`"""
+        return self.site_data_dir
+
+    @property
+    def user_cache_dir(self) -> str:
+        """
+        :return: cache directory tied to the user (if opinionated with ``Cache`` folder within ``$appname``) e.g.
+         ``%USERPROFILE%\\AppData\\Local\\$appauthor\\$appname\\Cache\\$version``
+        """
+        path = os.path.normpath(get_win_folder("CSIDL_LOCAL_APPDATA"))
+        return self._append_parts(path, opinion_value="Cache")
+
+    @property
+    def user_state_dir(self) -> str:
+        """:return: state directory tied to the user, same as `user_data_dir`"""
+        return self.user_data_dir
+
+    @property
+    def user_log_dir(self) -> str:
+        """
+        :return: log directory tied to the user, same as `user_data_dir` if not opinionated else ``Logs`` in it
+        """
+        path = self.user_data_dir
+        if self.opinion:
+            path = os.path.join(path, "Logs")
+        return path
+
+    @property
+    def user_documents_dir(self) -> str:
+        """
+        :return: documents directory tied to the user e.g. ``%USERPROFILE%\\Documents``
+        """
+        return os.path.normpath(get_win_folder("CSIDL_PERSONAL"))
+
+    @property
+    def user_runtime_dir(self) -> str:
+        """
+        :return: runtime directory tied to the user, e.g.
+         ``%USERPROFILE%\\AppData\\Local\\Temp\\$appauthor\\$appname``
+        """
+        path = os.path.normpath(os.path.join(get_win_folder("CSIDL_LOCAL_APPDATA"), "Temp"))
+        return self._append_parts(path)
+
+
+def get_win_folder_from_env_vars(csidl_name: str) -> str:
+    """Get folder from environment variables."""
+    if csidl_name == "CSIDL_PERSONAL":  # does not have an environment name
+        return os.path.join(os.path.normpath(os.environ["USERPROFILE"]), "Documents")
+
+    env_var_name = {
+        "CSIDL_APPDATA": "APPDATA",
+        "CSIDL_COMMON_APPDATA": "ALLUSERSPROFILE",
+        "CSIDL_LOCAL_APPDATA": "LOCALAPPDATA",
+    }.get(csidl_name)
+    if env_var_name is None:
+        raise ValueError(f"Unknown CSIDL name: {csidl_name}")
+    result = os.environ.get(env_var_name)
+    if result is None:
+        raise ValueError(f"Unset environment variable: {env_var_name}")
+    return result
+
+
+def get_win_folder_from_registry(csidl_name: str) -> str:
+    """Get folder from the registry.
+
+    This is a fallback technique at best. I'm not sure if using the
+    registry for this guarantees us the correct answer for all CSIDL_*
+    names.
+    """
+    shell_folder_name = {
+        "CSIDL_APPDATA": "AppData",
+        "CSIDL_COMMON_APPDATA": "Common AppData",
+        "CSIDL_LOCAL_APPDATA": "Local AppData",
+        "CSIDL_PERSONAL": "Personal",
+    }.get(csidl_name)
+    if shell_folder_name is None:
+        raise ValueError(f"Unknown CSIDL name: {csidl_name}")
+    if sys.platform != "win32":  # only needed for mypy type checker to know that this code runs only on Windows
+        raise NotImplementedError
+    import winreg
+
+    key = winreg.OpenKey(winreg.HKEY_CURRENT_USER, r"Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders")
+    directory, _ = winreg.QueryValueEx(key, shell_folder_name)
+    return str(directory)
+
+
+def get_win_folder_via_ctypes(csidl_name: str) -> str:
+    """Get folder with ctypes."""
+    csidl_const = {
+        "CSIDL_APPDATA": 26,
+        "CSIDL_COMMON_APPDATA": 35,
+        "CSIDL_LOCAL_APPDATA": 28,
+        "CSIDL_PERSONAL": 5,
+    }.get(csidl_name)
+    if csidl_const is None:
+        raise ValueError(f"Unknown CSIDL name: {csidl_name}")
+
+    buf = ctypes.create_unicode_buffer(1024)
+    windll = getattr(ctypes, "windll")  # noqa: B009 # using getattr to avoid false positive with mypy type checker
+    windll.shell32.SHGetFolderPathW(None, csidl_const, None, 0, buf)
+
+    # Downgrade to short path name if it has highbit chars.
+    if any(ord(c) > 255 for c in buf):
+        buf2 = ctypes.create_unicode_buffer(1024)
+        if windll.kernel32.GetShortPathNameW(buf.value, buf2, 1024):
+            buf = buf2
+
+    return buf.value
+
+
+def _pick_get_win_folder() -> Callable[[str], str]:
+    if hasattr(ctypes, "windll"):
+        return get_win_folder_via_ctypes
+    try:
+        import winreg  # noqa: F401
+    except ImportError:
+        return get_win_folder_from_env_vars
+    else:
+        return get_win_folder_from_registry
+
+
+get_win_folder = lru_cache(maxsize=None)(_pick_get_win_folder())
+
+__all__ = [
+    "Windows",
+]
diff --git a/third_party/python/setuptools/pkg_resources/_vendor/typing_extensions.py b/third_party/python/setuptools/pkg_resources/_vendor/typing_extensions.py
new file mode 100644
index 0000000000..ef42417c20
--- /dev/null
+++ b/third_party/python/setuptools/pkg_resources/_vendor/typing_extensions.py
@@ -0,0 +1,2209 @@
+import abc
+import collections
+import collections.abc
+import functools
+import operator
+import sys
+import types as _types
+import typing
+
+
+__all__ = [
+    # Super-special typing primitives.
+    'Any',
+    'ClassVar',
+    'Concatenate',
+    'Final',
+    'LiteralString',
+    'ParamSpec',
+    'ParamSpecArgs',
+    'ParamSpecKwargs',
+    'Self',
+    'Type',
+    'TypeVar',
+    'TypeVarTuple',
+    'Unpack',
+
+    # ABCs (from collections.abc).
+    'Awaitable',
+    'AsyncIterator',
+    'AsyncIterable',
+    'Coroutine',
+    'AsyncGenerator',
+    'AsyncContextManager',
+    'ChainMap',
+
+    # Concrete collection types.
+    'ContextManager',
+    'Counter',
+    'Deque',
+    'DefaultDict',
+    'NamedTuple',
+    'OrderedDict',
+    'TypedDict',
+
+    # Structural checks, a.k.a. protocols.
+    'SupportsIndex',
+
+    # One-off things.
+    'Annotated',
+    'assert_never',
+    'assert_type',
+    'clear_overloads',
+    'dataclass_transform',
+    'get_overloads',
+    'final',
+    'get_args',
+    'get_origin',
+    'get_type_hints',
+    'IntVar',
+    'is_typeddict',
+    'Literal',
+    'NewType',
+    'overload',
+    'override',
+    'Protocol',
+    'reveal_type',
+    'runtime',
+    'runtime_checkable',
+    'Text',
+    'TypeAlias',
+    'TypeGuard',
+    'TYPE_CHECKING',
+    'Never',
+    'NoReturn',
+    'Required',
+    'NotRequired',
+]
+
+# for backward compatibility
+PEP_560 = True
+GenericMeta = type
+
+# The functions below are modified copies of typing internal helpers.
+# They are needed by _ProtocolMeta and they provide support for PEP 646.
+
+_marker = object()
+
+
+def _check_generic(cls, parameters, elen=_marker):
+    """Check correct count for parameters of a generic cls (internal helper).
+    This gives a nice error message in case of count mismatch.
+    """
+    if not elen:
+        raise TypeError(f"{cls} is not a generic class")
+    if elen is _marker:
+        if not hasattr(cls, "__parameters__") or not cls.__parameters__:
+            raise TypeError(f"{cls} is not a generic class")
+        elen = len(cls.__parameters__)
+    alen = len(parameters)
+    if alen != elen:
+        if hasattr(cls, "__parameters__"):
+            parameters = [p for p in cls.__parameters__ if not _is_unpack(p)]
+            num_tv_tuples = sum(isinstance(p, TypeVarTuple) for p in parameters)
+            if (num_tv_tuples > 0) and (alen >= elen - num_tv_tuples):
+                return
+        raise TypeError(f"Too {'many' if alen > elen else 'few'} parameters for {cls};"
+                        f" actual {alen}, expected {elen}")
+
+
+if sys.version_info >= (3, 10):
+    def _should_collect_from_parameters(t):
+        return isinstance(
+            t, (typing._GenericAlias, _types.GenericAlias, _types.UnionType)
+        )
+elif sys.version_info >= (3, 9):
+    def _should_collect_from_parameters(t):
+        return isinstance(t, (typing._GenericAlias, _types.GenericAlias))
+else:
+    def _should_collect_from_parameters(t):
+        return isinstance(t, typing._GenericAlias) and not t._special
+
+
+def _collect_type_vars(types, typevar_types=None):
+    """Collect all type variable contained in types in order of
+    first appearance (lexicographic order). For example::
+
+        _collect_type_vars((T, List[S, T])) == (T, S)
+    """
+    if typevar_types is None:
+        typevar_types = typing.TypeVar
+    tvars = []
+    for t in types:
+        if (
+            isinstance(t, typevar_types) and
+            t not in tvars and
+            not _is_unpack(t)
+        ):
+            tvars.append(t)
+        if _should_collect_from_parameters(t):
+            tvars.extend([t for t in t.__parameters__ if t not in tvars])
+    return tuple(tvars)
+
+
+NoReturn = typing.NoReturn
+
+# Some unconstrained type variables.  These are used by the container types.
+# (These are not for export.)
+T = typing.TypeVar('T')  # Any type.
+KT = typing.TypeVar('KT')  # Key type.
+VT = typing.TypeVar('VT')  # Value type.
+T_co = typing.TypeVar('T_co', covariant=True)  # Any type covariant containers.
+T_contra = typing.TypeVar('T_contra', contravariant=True)  # Ditto contravariant.
+
+
+if sys.version_info >= (3, 11):
+    from typing import Any
+else:
+
+    class _AnyMeta(type):
+        def __instancecheck__(self, obj):
+            if self is Any:
+                raise TypeError("typing_extensions.Any cannot be used with isinstance()")
+            return super().__instancecheck__(obj)
+
+        def __repr__(self):
+            if self is Any:
+                return "typing_extensions.Any"
+            return super().__repr__()
+
+    class Any(metaclass=_AnyMeta):
+        """Special type indicating an unconstrained type.
+        - Any is compatible with every type.
+        - Any assumed to have all methods.
+        - All values assumed to be instances of Any.
+        Note that all the above statements are true from the point of view of
+        static type checkers. At runtime, Any should not be used with instance
+        checks.
+        """
+        def __new__(cls, *args, **kwargs):
+            if cls is Any:
+                raise TypeError("Any cannot be instantiated")
+            return super().__new__(cls, *args, **kwargs)
+
+
+ClassVar = typing.ClassVar
+
+# On older versions of typing there is an internal class named "Final".
+# 3.8+
+if hasattr(typing, 'Final') and sys.version_info[:2] >= (3, 7):
+    Final = typing.Final
+# 3.7
+else:
+    class _FinalForm(typing._SpecialForm, _root=True):
+
+        def __repr__(self):
+            return 'typing_extensions.' + self._name
+
+        def __getitem__(self, parameters):
+            item = typing._type_check(parameters,
+                                      f'{self._name} accepts only a single type.')
+            return typing._GenericAlias(self, (item,))
+
+    Final = _FinalForm('Final',
+                       doc="""A special typing construct to indicate that a name
+                       cannot be re-assigned or overridden in a subclass.
+                       For example:
+
+                           MAX_SIZE: Final = 9000
+                           MAX_SIZE += 1  # Error reported by type checker
+
+                           class Connection:
+                               TIMEOUT: Final[int] = 10
+                           class FastConnector(Connection):
+                               TIMEOUT = 1  # Error reported by type checker
+
+                       There is no runtime checking of these properties.""")
+
+if sys.version_info >= (3, 11):
+    final = typing.final
+else:
+    # @final exists in 3.8+, but we backport it for all versions
+    # before 3.11 to keep support for the __final__ attribute.
+    # See https://bugs.python.org/issue46342
+    def final(f):
+        """This decorator can be used to indicate to type checkers that
+        the decorated method cannot be overridden, and decorated class
+        cannot be subclassed. For example:
+
+            class Base:
+                @final
+                def done(self) -> None:
+                    ...
+            class Sub(Base):
+                def done(self) -> None:  # Error reported by type checker
+                    ...
+            @final
+            class Leaf:
+                ...
+            class Other(Leaf):  # Error reported by type checker
+                ...
+
+        There is no runtime checking of these properties. The decorator
+        sets the ``__final__`` attribute to ``True`` on the decorated object
+        to allow runtime introspection.
+        """
+        try:
+            f.__final__ = True
+        except (AttributeError, TypeError):
+            # Skip the attribute silently if it is not writable.
+            # AttributeError happens if the object has __slots__ or a
+            # read-only property, TypeError if it's a builtin class.
+            pass
+        return f
+
+
+def IntVar(name):
+    return typing.TypeVar(name)
+
+
+# 3.8+:
+if hasattr(typing, 'Literal'):
+    Literal = typing.Literal
+# 3.7:
+else:
+    class _LiteralForm(typing._SpecialForm, _root=True):
+
+        def __repr__(self):
+            return 'typing_extensions.' + self._name
+
+        def __getitem__(self, parameters):
+            return typing._GenericAlias(self, parameters)
+
+    Literal = _LiteralForm('Literal',
+                           doc="""A type that can be used to indicate to type checkers
+                           that the corresponding value has a value literally equivalent
+                           to the provided parameter. For example:
+
+                               var: Literal[4] = 4
+
+                           The type checker understands that 'var' is literally equal to
+                           the value 4 and no other value.
+
+                           Literal[...] cannot be subclassed. There is no runtime
+                           checking verifying that the parameter is actually a value
+                           instead of a type.""")
+
+
+_overload_dummy = typing._overload_dummy  # noqa
+
+
+if hasattr(typing, "get_overloads"):  # 3.11+
+    overload = typing.overload
+    get_overloads = typing.get_overloads
+    clear_overloads = typing.clear_overloads
+else:
+    # {module: {qualname: {firstlineno: func}}}
+    _overload_registry = collections.defaultdict(
+        functools.partial(collections.defaultdict, dict)
+    )
+
+    def overload(func):
+        """Decorator for overloaded functions/methods.
+
+        In a stub file, place two or more stub definitions for the same
+        function in a row, each decorated with @overload.  For example:
+
+        @overload
+        def utf8(value: None) -> None: ...
+        @overload
+        def utf8(value: bytes) -> bytes: ...
+        @overload
+        def utf8(value: str) -> bytes: ...
+
+        In a non-stub file (i.e. a regular .py file), do the same but
+        follow it with an implementation.  The implementation should *not*
+        be decorated with @overload.  For example:
+
+        @overload
+        def utf8(value: None) -> None: ...
+        @overload
+        def utf8(value: bytes) -> bytes: ...
+        @overload
+        def utf8(value: str) -> bytes: ...
+        def utf8(value):
+            # implementation goes here
+
+        The overloads for a function can be retrieved at runtime using the
+        get_overloads() function.
+        """
+        # classmethod and staticmethod
+        f = getattr(func, "__func__", func)
+        try:
+            _overload_registry[f.__module__][f.__qualname__][
+                f.__code__.co_firstlineno
+            ] = func
+        except AttributeError:
+            # Not a normal function; ignore.
+            pass
+        return _overload_dummy
+
+    def get_overloads(func):
+        """Return all defined overloads for *func* as a sequence."""
+        # classmethod and staticmethod
+        f = getattr(func, "__func__", func)
+        if f.__module__ not in _overload_registry:
+            return []
+        mod_dict = _overload_registry[f.__module__]
+        if f.__qualname__ not in mod_dict:
+            return []
+        return list(mod_dict[f.__qualname__].values())
+
+    def clear_overloads():
+        """Clear all overloads in the registry."""
+        _overload_registry.clear()
+
+
+# This is not a real generic class.  Don't use outside annotations.
+Type = typing.Type
+
+# Various ABCs mimicking those in collections.abc.
+# A few are simply re-exported for completeness.
+
+
+Awaitable = typing.Awaitable
+Coroutine = typing.Coroutine
+AsyncIterable = typing.AsyncIterable
+AsyncIterator = typing.AsyncIterator
+Deque = typing.Deque
+ContextManager = typing.ContextManager
+AsyncContextManager = typing.AsyncContextManager
+DefaultDict = typing.DefaultDict
+
+# 3.7.2+
+if hasattr(typing, 'OrderedDict'):
+    OrderedDict = typing.OrderedDict
+# 3.7.0-3.7.2
+else:
+    OrderedDict = typing._alias(collections.OrderedDict, (KT, VT))
+
+Counter = typing.Counter
+ChainMap = typing.ChainMap
+AsyncGenerator = typing.AsyncGenerator
+NewType = typing.NewType
+Text = typing.Text
+TYPE_CHECKING = typing.TYPE_CHECKING
+
+
+_PROTO_WHITELIST = ['Callable', 'Awaitable',
+                    'Iterable', 'Iterator', 'AsyncIterable', 'AsyncIterator',
+                    'Hashable', 'Sized', 'Container', 'Collection', 'Reversible',
+                    'ContextManager', 'AsyncContextManager']
+
+
+def _get_protocol_attrs(cls):
+    attrs = set()
+    for base in cls.__mro__[:-1]:  # without object
+        if base.__name__ in ('Protocol', 'Generic'):
+            continue
+        annotations = getattr(base, '__annotations__', {})
+        for attr in list(base.__dict__.keys()) + list(annotations.keys()):
+            if (not attr.startswith('_abc_') and attr not in (
+                    '__abstractmethods__', '__annotations__', '__weakref__',
+                    '_is_protocol', '_is_runtime_protocol', '__dict__',
+                    '__args__', '__slots__',
+                    '__next_in_mro__', '__parameters__', '__origin__',
+                    '__orig_bases__', '__extra__', '__tree_hash__',
+                    '__doc__', '__subclasshook__', '__init__', '__new__',
+                    '__module__', '_MutableMapping__marker', '_gorg')):
+                attrs.add(attr)
+    return attrs
+
+
+def _is_callable_members_only(cls):
+    return all(callable(getattr(cls, attr, None)) for attr in _get_protocol_attrs(cls))
+
+
+def _maybe_adjust_parameters(cls):
+    """Helper function used in Protocol.__init_subclass__ and _TypedDictMeta.__new__.
+
+    The contents of this function are very similar
+    to logic found in typing.Generic.__init_subclass__
+    on the CPython main branch.
+    """
+    tvars = []
+    if '__orig_bases__' in cls.__dict__:
+        tvars = typing._collect_type_vars(cls.__orig_bases__)
+        # Look for Generic[T1, ..., Tn] or Protocol[T1, ..., Tn].
+        # If found, tvars must be a subset of it.
+        # If not found, tvars is it.
+        # Also check for and reject plain Generic,
+        # and reject multiple Generic[...] and/or Protocol[...].
+        gvars = None
+        for base in cls.__orig_bases__:
+            if (isinstance(base, typing._GenericAlias) and
+                    base.__origin__ in (typing.Generic, Protocol)):
+                # for error messages
+                the_base = base.__origin__.__name__
+                if gvars is not None:
+                    raise TypeError(
+                        "Cannot inherit from Generic[...]"
+                        " and/or Protocol[...] multiple types.")
+                gvars = base.__parameters__
+        if gvars is None:
+            gvars = tvars
+        else:
+            tvarset = set(tvars)
+            gvarset = set(gvars)
+            if not tvarset <= gvarset:
+                s_vars = ', '.join(str(t) for t in tvars if t not in gvarset)
+                s_args = ', '.join(str(g) for g in gvars)
+                raise TypeError(f"Some type variables ({s_vars}) are"
+                                f" not listed in {the_base}[{s_args}]")
+            tvars = gvars
+    cls.__parameters__ = tuple(tvars)
+
+
+# 3.8+
+if hasattr(typing, 'Protocol'):
+    Protocol = typing.Protocol
+# 3.7
+else:
+
+    def _no_init(self, *args, **kwargs):
+        if type(self)._is_protocol:
+            raise TypeError('Protocols cannot be instantiated')
+
+    class _ProtocolMeta(abc.ABCMeta):  # noqa: B024
+        # This metaclass is a bit unfortunate and exists only because of the lack
+        # of __instancehook__.
+        def __instancecheck__(cls, instance):
+            # We need this method for situations where attributes are
+            # assigned in __init__.
+            if ((not getattr(cls, '_is_protocol', False) or
+                 _is_callable_members_only(cls)) and
+                    issubclass(instance.__class__, cls)):
+                return True
+            if cls._is_protocol:
+                if all(hasattr(instance, attr) and
+                       (not callable(getattr(cls, attr, None)) or
+                        getattr(instance, attr) is not None)
+                       for attr in _get_protocol_attrs(cls)):
+                    return True
+            return super().__instancecheck__(instance)
+
+    class Protocol(metaclass=_ProtocolMeta):
+        # There is quite a lot of overlapping code with typing.Generic.
+        # Unfortunately it is hard to avoid this while these live in two different
+        # modules. The duplicated code will be removed when Protocol is moved to typing.
+        """Base class for protocol classes. Protocol classes are defined as::
+
+            class Proto(Protocol):
+                def meth(self) -> int:
+                    ...
+
+        Such classes are primarily used with static type checkers that recognize
+        structural subtyping (static duck-typing), for example::
+
+            class C:
+                def meth(self) -> int:
+                    return 0
+
+            def func(x: Proto) -> int:
+                return x.meth()
+
+            func(C())  # Passes static type check
+
+        See PEP 544 for details. Protocol classes decorated with
+        @typing_extensions.runtime act as simple-minded runtime protocol that checks
+        only the presence of given attributes, ignoring their type signatures.
+
+        Protocol classes can be generic, they are defined as::
+
+            class GenProto(Protocol[T]):
+                def meth(self) -> T:
+                    ...
+        """
+        __slots__ = ()
+        _is_protocol = True
+
+        def __new__(cls, *args, **kwds):
+            if cls is Protocol:
+                raise TypeError("Type Protocol cannot be instantiated; "
+                                "it can only be used as a base class")
+            return super().__new__(cls)
+
+        @typing._tp_cache
+        def __class_getitem__(cls, params):
+            if not isinstance(params, tuple):
+                params = (params,)
+            if not params and cls is not typing.Tuple:
+                raise TypeError(
+                    f"Parameter list to {cls.__qualname__}[...] cannot be empty")
+            msg = "Parameters to generic types must be types."
+            params = tuple(typing._type_check(p, msg) for p in params)  # noqa
+            if cls is Protocol:
+                # Generic can only be subscripted with unique type variables.
+                if not all(isinstance(p, typing.TypeVar) for p in params):
+                    i = 0
+                    while isinstance(params[i], typing.TypeVar):
+                        i += 1
+                    raise TypeError(
+                        "Parameters to Protocol[...] must all be type variables."
+                        f" Parameter {i + 1} is {params[i]}")
+                if len(set(params)) != len(params):
+                    raise TypeError(
+                        "Parameters to Protocol[...] must all be unique")
+            else:
+                # Subscripting a regular Generic subclass.
+                _check_generic(cls, params, len(cls.__parameters__))
+            return typing._GenericAlias(cls, params)
+
+        def __init_subclass__(cls, *args, **kwargs):
+            if '__orig_bases__' in cls.__dict__:
+                error = typing.Generic in cls.__orig_bases__
+            else:
+                error = typing.Generic in cls.__bases__
+            if error:
+                raise TypeError("Cannot inherit from plain Generic")
+            _maybe_adjust_parameters(cls)
+
+            # Determine if this is a protocol or a concrete subclass.
+            if not cls.__dict__.get('_is_protocol', None):
+                cls._is_protocol = any(b is Protocol for b in cls.__bases__)
+
+            # Set (or override) the protocol subclass hook.
+            def _proto_hook(other):
+                if not cls.__dict__.get('_is_protocol', None):
+                    return NotImplemented
+                if not getattr(cls, '_is_runtime_protocol', False):
+                    if sys._getframe(2).f_globals['__name__'] in ['abc', 'functools']:
+                        return NotImplemented
+                    raise TypeError("Instance and class checks can only be used with"
+                                    " @runtime protocols")
+                if not _is_callable_members_only(cls):
+                    if sys._getframe(2).f_globals['__name__'] in ['abc', 'functools']:
+                        return NotImplemented
+                    raise TypeError("Protocols with non-method members"
+                                    " don't support issubclass()")
+                if not isinstance(other, type):
+                    # Same error as for issubclass(1, int)
+                    raise TypeError('issubclass() arg 1 must be a class')
+                for attr in _get_protocol_attrs(cls):
+                    for base in other.__mro__:
+                        if attr in base.__dict__:
+                            if base.__dict__[attr] is None:
+                                return NotImplemented
+                            break
+                        annotations = getattr(base, '__annotations__', {})
+                        if (isinstance(annotations, typing.Mapping) and
+                                attr in annotations and
+                                isinstance(other, _ProtocolMeta) and
+                                other._is_protocol):
+                            break
+                    else:
+                        return NotImplemented
+                return True
+            if '__subclasshook__' not in cls.__dict__:
+                cls.__subclasshook__ = _proto_hook
+
+            # We have nothing more to do for non-protocols.
+            if not cls._is_protocol:
+                return
+
+            # Check consistency of bases.
+            for base in cls.__bases__:
+                if not (base in (object, typing.Generic) or
+                        base.__module__ == 'collections.abc' and
+                        base.__name__ in _PROTO_WHITELIST or
+                        isinstance(base, _ProtocolMeta) and base._is_protocol):
+                    raise TypeError('Protocols can only inherit from other'
+                                    f' protocols, got {repr(base)}')
+            cls.__init__ = _no_init
+
+
+# 3.8+
+if hasattr(typing, 'runtime_checkable'):
+    runtime_checkable = typing.runtime_checkable
+# 3.7
+else:
+    def runtime_checkable(cls):
+        """Mark a protocol class as a runtime protocol, so that it
+        can be used with isinstance() and issubclass(). Raise TypeError
+        if applied to a non-protocol class.
+
+        This allows a simple-minded structural check very similar to the
+        one-offs in collections.abc such as Hashable.
+        """
+        if not isinstance(cls, _ProtocolMeta) or not cls._is_protocol:
+            raise TypeError('@runtime_checkable can be only applied to protocol classes,'
+                            f' got {cls!r}')
+        cls._is_runtime_protocol = True
+        return cls
+
+
+# Exists for backwards compatibility.
+runtime = runtime_checkable
+
+
+# 3.8+
+if hasattr(typing, 'SupportsIndex'):
+    SupportsIndex = typing.SupportsIndex
+# 3.7
+else:
+    @runtime_checkable
+    class SupportsIndex(Protocol):
+        __slots__ = ()
+
+        @abc.abstractmethod
+        def __index__(self) -> int:
+            pass
+
+
+if hasattr(typing, "Required"):
+    # The standard library TypedDict in Python 3.8 does not store runtime information
+    # about which (if any) keys are optional.  See https://bugs.python.org/issue38834
+    # The standard library TypedDict in Python 3.9.0/1 does not honour the "total"
+    # keyword with old-style TypedDict().  See https://bugs.python.org/issue42059
+    # The standard library TypedDict below Python 3.11 does not store runtime
+    # information about optional and required keys when using Required or NotRequired.
+    # Generic TypedDicts are also impossible using typing.TypedDict on Python <3.11.
+    TypedDict = typing.TypedDict
+    _TypedDictMeta = typing._TypedDictMeta
+    is_typeddict = typing.is_typeddict
+else:
+    def _check_fails(cls, other):
+        try:
+            if sys._getframe(1).f_globals['__name__'] not in ['abc',
+                                                              'functools',
+                                                              'typing']:
+                # Typed dicts are only for static structural subtyping.
+                raise TypeError('TypedDict does not support instance and class checks')
+        except (AttributeError, ValueError):
+            pass
+        return False
+
+    def _dict_new(*args, **kwargs):
+        if not args:
+            raise TypeError('TypedDict.__new__(): not enough arguments')
+        _, args = args[0], args[1:]  # allow the "cls" keyword be passed
+        return dict(*args, **kwargs)
+
+    _dict_new.__text_signature__ = '($cls, _typename, _fields=None, /, **kwargs)'
+
+    def _typeddict_new(*args, total=True, **kwargs):
+        if not args:
+            raise TypeError('TypedDict.__new__(): not enough arguments')
+        _, args = args[0], args[1:]  # allow the "cls" keyword be passed
+        if args:
+            typename, args = args[0], args[1:]  # allow the "_typename" keyword be passed
+        elif '_typename' in kwargs:
+            typename = kwargs.pop('_typename')
+            import warnings
+            warnings.warn("Passing '_typename' as keyword argument is deprecated",
+                          DeprecationWarning, stacklevel=2)
+        else:
+            raise TypeError("TypedDict.__new__() missing 1 required positional "
+                            "argument: '_typename'")
+        if args:
+            try:
+                fields, = args  # allow the "_fields" keyword be passed
+            except ValueError:
+                raise TypeError('TypedDict.__new__() takes from 2 to 3 '
+                                f'positional arguments but {len(args) + 2} '
+                                'were given')
+        elif '_fields' in kwargs and len(kwargs) == 1:
+            fields = kwargs.pop('_fields')
+            import warnings
+            warnings.warn("Passing '_fields' as keyword argument is deprecated",
+                          DeprecationWarning, stacklevel=2)
+        else:
+            fields = None
+
+        if fields is None:
+            fields = kwargs
+        elif kwargs:
+            raise TypeError("TypedDict takes either a dict or keyword arguments,"
+                            " but not both")
+
+        ns = {'__annotations__': dict(fields)}
+        try:
+            # Setting correct module is necessary to make typed dict classes pickleable.
+            ns['__module__'] = sys._getframe(1).f_globals.get('__name__', '__main__')
+        except (AttributeError, ValueError):
+            pass
+
+        return _TypedDictMeta(typename, (), ns, total=total)
+
+    _typeddict_new.__text_signature__ = ('($cls, _typename, _fields=None,'
+                                         ' /, *, total=True, **kwargs)')
+
+    class _TypedDictMeta(type):
+        def __init__(cls, name, bases, ns, total=True):
+            super().__init__(name, bases, ns)
+
+        def __new__(cls, name, bases, ns, total=True):
+            # Create new typed dict class object.
+            # This method is called directly when TypedDict is subclassed,
+            # or via _typeddict_new when TypedDict is instantiated. This way
+            # TypedDict supports all three syntaxes described in its docstring.
+            # Subclasses and instances of TypedDict return actual dictionaries
+            # via _dict_new.
+            ns['__new__'] = _typeddict_new if name == 'TypedDict' else _dict_new
+            # Don't insert typing.Generic into __bases__ here,
+            # or Generic.__init_subclass__ will raise TypeError
+            # in the super().__new__() call.
+            # Instead, monkey-patch __bases__ onto the class after it's been created.
+            tp_dict = super().__new__(cls, name, (dict,), ns)
+
+            if any(issubclass(base, typing.Generic) for base in bases):
+                tp_dict.__bases__ = (typing.Generic, dict)
+                _maybe_adjust_parameters(tp_dict)
+
+            annotations = {}
+            own_annotations = ns.get('__annotations__', {})
+            msg = "TypedDict('Name', {f0: t0, f1: t1, ...}); each t must be a type"
+            own_annotations = {
+                n: typing._type_check(tp, msg) for n, tp in own_annotations.items()
+            }
+            required_keys = set()
+            optional_keys = set()
+
+            for base in bases:
+                annotations.update(base.__dict__.get('__annotations__', {}))
+                required_keys.update(base.__dict__.get('__required_keys__', ()))
+                optional_keys.update(base.__dict__.get('__optional_keys__', ()))
+
+            annotations.update(own_annotations)
+            for annotation_key, annotation_type in own_annotations.items():
+                annotation_origin = get_origin(annotation_type)
+                if annotation_origin is Annotated:
+                    annotation_args = get_args(annotation_type)
+                    if annotation_args:
+                        annotation_type = annotation_args[0]
+                        annotation_origin = get_origin(annotation_type)
+
+                if annotation_origin is Required:
+                    required_keys.add(annotation_key)
+                elif annotation_origin is NotRequired:
+                    optional_keys.add(annotation_key)
+                elif total:
+                    required_keys.add(annotation_key)
+                else:
+                    optional_keys.add(annotation_key)
+
+            tp_dict.__annotations__ = annotations
+            tp_dict.__required_keys__ = frozenset(required_keys)
+            tp_dict.__optional_keys__ = frozenset(optional_keys)
+            if not hasattr(tp_dict, '__total__'):
+                tp_dict.__total__ = total
+            return tp_dict
+
+        __instancecheck__ = __subclasscheck__ = _check_fails
+
+    TypedDict = _TypedDictMeta('TypedDict', (dict,), {})
+    TypedDict.__module__ = __name__
+    TypedDict.__doc__ = \
+        """A simple typed name space. At runtime it is equivalent to a plain dict.
+
+        TypedDict creates a dictionary type that expects all of its
+        instances to have a certain set of keys, with each key
+        associated with a value of a consistent type. This expectation
+        is not checked at runtime but is only enforced by type checkers.
+        Usage::
+
+            class Point2D(TypedDict):
+                x: int
+                y: int
+                label: str
+
+            a: Point2D = {'x': 1, 'y': 2, 'label': 'good'}  # OK
+            b: Point2D = {'z': 3, 'label': 'bad'}           # Fails type check
+
+            assert Point2D(x=1, y=2, label='first') == dict(x=1, y=2, label='first')
+
+        The type info can be accessed via the Point2D.__annotations__ dict, and
+        the Point2D.__required_keys__ and Point2D.__optional_keys__ frozensets.
+        TypedDict supports two additional equivalent forms::
+
+            Point2D = TypedDict('Point2D', x=int, y=int, label=str)
+            Point2D = TypedDict('Point2D', {'x': int, 'y': int, 'label': str})
+
+        The class syntax is only supported in Python 3.6+, while two other
+        syntax forms work for Python 2.7 and 3.2+
+        """
+
+    if hasattr(typing, "_TypedDictMeta"):
+        _TYPEDDICT_TYPES = (typing._TypedDictMeta, _TypedDictMeta)
+    else:
+        _TYPEDDICT_TYPES = (_TypedDictMeta,)
+
+    def is_typeddict(tp):
+        """Check if an annotation is a TypedDict class
+
+        For example::
+            class Film(TypedDict):
+                title: str
+                year: int
+
+            is_typeddict(Film)  # => True
+            is_typeddict(Union[list, str])  # => False
+        """
+        return isinstance(tp, tuple(_TYPEDDICT_TYPES))
+
+
+if hasattr(typing, "assert_type"):
+    assert_type = typing.assert_type
+
+else:
+    def assert_type(__val, __typ):
+        """Assert (to the type checker) that the value is of the given type.
+
+        When the type checker encounters a call to assert_type(), it
+        emits an error if the value is not of the specified type::
+
+            def greet(name: str) -> None:
+                assert_type(name, str)  # ok
+                assert_type(name, int)  # type checker error
+
+        At runtime this returns the first argument unchanged and otherwise
+        does nothing.
+        """
+        return __val
+
+
+if hasattr(typing, "Required"):
+    get_type_hints = typing.get_type_hints
+else:
+    import functools
+    import types
+
+    # replaces _strip_annotations()
+    def _strip_extras(t):
+        """Strips Annotated, Required and NotRequired from a given type."""
+        if isinstance(t, _AnnotatedAlias):
+            return _strip_extras(t.__origin__)
+        if hasattr(t, "__origin__") and t.__origin__ in (Required, NotRequired):
+            return _strip_extras(t.__args__[0])
+        if isinstance(t, typing._GenericAlias):
+            stripped_args = tuple(_strip_extras(a) for a in t.__args__)
+            if stripped_args == t.__args__:
+                return t
+            return t.copy_with(stripped_args)
+        if hasattr(types, "GenericAlias") and isinstance(t, types.GenericAlias):
+            stripped_args = tuple(_strip_extras(a) for a in t.__args__)
+            if stripped_args == t.__args__:
+                return t
+            return types.GenericAlias(t.__origin__, stripped_args)
+        if hasattr(types, "UnionType") and isinstance(t, types.UnionType):
+            stripped_args = tuple(_strip_extras(a) for a in t.__args__)
+            if stripped_args == t.__args__:
+                return t
+            return functools.reduce(operator.or_, stripped_args)
+
+        return t
+
+    def get_type_hints(obj, globalns=None, localns=None, include_extras=False):
+        """Return type hints for an object.
+
+        This is often the same as obj.__annotations__, but it handles
+        forward references encoded as string literals, adds Optional[t] if a
+        default value equal to None is set and recursively replaces all
+        'Annotated[T, ...]', 'Required[T]' or 'NotRequired[T]' with 'T'
+        (unless 'include_extras=True').
+
+        The argument may be a module, class, method, or function. The annotations
+        are returned as a dictionary. For classes, annotations include also
+        inherited members.
+
+        TypeError is raised if the argument is not of a type that can contain
+        annotations, and an empty dictionary is returned if no annotations are
+        present.
+
+        BEWARE -- the behavior of globalns and localns is counterintuitive
+        (unless you are familiar with how eval() and exec() work).  The
+        search order is locals first, then globals.
+
+        - If no dict arguments are passed, an attempt is made to use the
+          globals from obj (or the respective module's globals for classes),
+          and these are also used as the locals.  If the object does not appear
+          to have globals, an empty dictionary is used.
+
+        - If one dict argument is passed, it is used for both globals and
+          locals.
+
+        - If two dict arguments are passed, they specify globals and
+          locals, respectively.
+        """
+        if hasattr(typing, "Annotated"):
+            hint = typing.get_type_hints(
+                obj, globalns=globalns, localns=localns, include_extras=True
+            )
+        else:
+            hint = typing.get_type_hints(obj, globalns=globalns, localns=localns)
+        if include_extras:
+            return hint
+        return {k: _strip_extras(t) for k, t in hint.items()}
+
+
+# Python 3.9+ has PEP 593 (Annotated)
+if hasattr(typing, 'Annotated'):
+    Annotated = typing.Annotated
+    # Not exported and not a public API, but needed for get_origin() and get_args()
+    # to work.
+    _AnnotatedAlias = typing._AnnotatedAlias
+# 3.7-3.8
+else:
+    class _AnnotatedAlias(typing._GenericAlias, _root=True):
+        """Runtime representation of an annotated type.
+
+        At its core 'Annotated[t, dec1, dec2, ...]' is an alias for the type 't'
+        with extra annotations. The alias behaves like a normal typing alias,
+        instantiating is the same as instantiating the underlying type, binding
+        it to types is also the same.
+        """
+        def __init__(self, origin, metadata):
+            if isinstance(origin, _AnnotatedAlias):
+                metadata = origin.__metadata__ + metadata
+                origin = origin.__origin__
+            super().__init__(origin, origin)
+            self.__metadata__ = metadata
+
+        def copy_with(self, params):
+            assert len(params) == 1
+            new_type = params[0]
+            return _AnnotatedAlias(new_type, self.__metadata__)
+
+        def __repr__(self):
+            return (f"typing_extensions.Annotated[{typing._type_repr(self.__origin__)}, "
+                    f"{', '.join(repr(a) for a in self.__metadata__)}]")
+
+        def __reduce__(self):
+            return operator.getitem, (
+                Annotated, (self.__origin__,) + self.__metadata__
+            )
+
+        def __eq__(self, other):
+            if not isinstance(other, _AnnotatedAlias):
+                return NotImplemented
+            if self.__origin__ != other.__origin__:
+                return False
+            return self.__metadata__ == other.__metadata__
+
+        def __hash__(self):
+            return hash((self.__origin__, self.__metadata__))
+
+    class Annotated:
+        """Add context specific metadata to a type.
+
+        Example: Annotated[int, runtime_check.Unsigned] indicates to the
+        hypothetical runtime_check module that this type is an unsigned int.
+        Every other consumer of this type can ignore this metadata and treat
+        this type as int.
+
+        The first argument to Annotated must be a valid type (and will be in
+        the __origin__ field), the remaining arguments are kept as a tuple in
+        the __extra__ field.
+
+        Details:
+
+        - It's an error to call `Annotated` with less than two arguments.
+        - Nested Annotated are flattened::
+
+            Annotated[Annotated[T, Ann1, Ann2], Ann3] == Annotated[T, Ann1, Ann2, Ann3]
+
+        - Instantiating an annotated type is equivalent to instantiating the
+        underlying type::
+
+            Annotated[C, Ann1](5) == C(5)
+
+        - Annotated can be used as a generic type alias::
+
+            Optimized = Annotated[T, runtime.Optimize()]
+            Optimized[int] == Annotated[int, runtime.Optimize()]
+
+            OptimizedList = Annotated[List[T], runtime.Optimize()]
+            OptimizedList[int] == Annotated[List[int], runtime.Optimize()]
+        """
+
+        __slots__ = ()
+
+        def __new__(cls, *args, **kwargs):
+            raise TypeError("Type Annotated cannot be instantiated.")
+
+        @typing._tp_cache
+        def __class_getitem__(cls, params):
+            if not isinstance(params, tuple) or len(params) < 2:
+                raise TypeError("Annotated[...] should be used "
+                                "with at least two arguments (a type and an "
+                                "annotation).")
+            allowed_special_forms = (ClassVar, Final)
+            if get_origin(params[0]) in allowed_special_forms:
+                origin = params[0]
+            else:
+                msg = "Annotated[t, ...]: t must be a type."
+                origin = typing._type_check(params[0], msg)
+            metadata = tuple(params[1:])
+            return _AnnotatedAlias(origin, metadata)
+
+        def __init_subclass__(cls, *args, **kwargs):
+            raise TypeError(
+                f"Cannot subclass {cls.__module__}.Annotated"
+            )
+
+# Python 3.8 has get_origin() and get_args() but those implementations aren't
+# Annotated-aware, so we can't use those. Python 3.9's versions don't support
+# ParamSpecArgs and ParamSpecKwargs, so only Python 3.10's versions will do.
+if sys.version_info[:2] >= (3, 10):
+    get_origin = typing.get_origin
+    get_args = typing.get_args
+# 3.7-3.9
+else:
+    try:
+        # 3.9+
+        from typing import _BaseGenericAlias
+    except ImportError:
+        _BaseGenericAlias = typing._GenericAlias
+    try:
+        # 3.9+
+        from typing import GenericAlias as _typing_GenericAlias
+    except ImportError:
+        _typing_GenericAlias = typing._GenericAlias
+
+    def get_origin(tp):
+        """Get the unsubscripted version of a type.
+
+        This supports generic types, Callable, Tuple, Union, Literal, Final, ClassVar
+        and Annotated. Return None for unsupported types. Examples::
+
+            get_origin(Literal[42]) is Literal
+            get_origin(int) is None
+            get_origin(ClassVar[int]) is ClassVar
+            get_origin(Generic) is Generic
+            get_origin(Generic[T]) is Generic
+            get_origin(Union[T, int]) is Union
+            get_origin(List[Tuple[T, T]][int]) == list
+            get_origin(P.args) is P
+        """
+        if isinstance(tp, _AnnotatedAlias):
+            return Annotated
+        if isinstance(tp, (typing._GenericAlias, _typing_GenericAlias, _BaseGenericAlias,
+                           ParamSpecArgs, ParamSpecKwargs)):
+            return tp.__origin__
+        if tp is typing.Generic:
+            return typing.Generic
+        return None
+
+    def get_args(tp):
+        """Get type arguments with all substitutions performed.
+
+        For unions, basic simplifications used by Union constructor are performed.
+        Examples::
+            get_args(Dict[str, int]) == (str, int)
+            get_args(int) == ()
+            get_args(Union[int, Union[T, int], str][int]) == (int, str)
+            get_args(Union[int, Tuple[T, int]][str]) == (int, Tuple[str, int])
+            get_args(Callable[[], T][int]) == ([], int)
+        """
+        if isinstance(tp, _AnnotatedAlias):
+            return (tp.__origin__,) + tp.__metadata__
+        if isinstance(tp, (typing._GenericAlias, _typing_GenericAlias)):
+            if getattr(tp, "_special", False):
+                return ()
+            res = tp.__args__
+            if get_origin(tp) is collections.abc.Callable and res[0] is not Ellipsis:
+                res = (list(res[:-1]), res[-1])
+            return res
+        return ()
+
+
+# 3.10+
+if hasattr(typing, 'TypeAlias'):
+    TypeAlias = typing.TypeAlias
+# 3.9
+elif sys.version_info[:2] >= (3, 9):
+    class _TypeAliasForm(typing._SpecialForm, _root=True):
+        def __repr__(self):
+            return 'typing_extensions.' + self._name
+
+    @_TypeAliasForm
+    def TypeAlias(self, parameters):
+        """Special marker indicating that an assignment should
+        be recognized as a proper type alias definition by type
+        checkers.
+
+        For example::
+
+            Predicate: TypeAlias = Callable[..., bool]
+
+        It's invalid when used anywhere except as in the example above.
+        """
+        raise TypeError(f"{self} is not subscriptable")
+# 3.7-3.8
+else:
+    class _TypeAliasForm(typing._SpecialForm, _root=True):
+        def __repr__(self):
+            return 'typing_extensions.' + self._name
+
+    TypeAlias = _TypeAliasForm('TypeAlias',
+                               doc="""Special marker indicating that an assignment should
+                               be recognized as a proper type alias definition by type
+                               checkers.
+
+                               For example::
+
+                                   Predicate: TypeAlias = Callable[..., bool]
+
+                               It's invalid when used anywhere except as in the example
+                               above.""")
+
+
+class _DefaultMixin:
+    """Mixin for TypeVarLike defaults."""
+
+    __slots__ = ()
+
+    def __init__(self, default):
+        if isinstance(default, (tuple, list)):
+            self.__default__ = tuple((typing._type_check(d, "Default must be a type")
+                                      for d in default))
+        elif default:
+            self.__default__ = typing._type_check(default, "Default must be a type")
+        else:
+            self.__default__ = None
+
+
+# Add default and infer_variance parameters from PEP 696 and 695
+class TypeVar(typing.TypeVar, _DefaultMixin, _root=True):
+    """Type variable."""
+
+    __module__ = 'typing'
+
+    def __init__(self, name, *constraints, bound=None,
+                 covariant=False, contravariant=False,
+                 default=None, infer_variance=False):
+        super().__init__(name, *constraints, bound=bound, covariant=covariant,
+                         contravariant=contravariant)
+        _DefaultMixin.__init__(self, default)
+        self.__infer_variance__ = infer_variance
+
+        # for pickling:
+        try:
+            def_mod = sys._getframe(1).f_globals.get('__name__', '__main__')
+        except (AttributeError, ValueError):
+            def_mod = None
+        if def_mod != 'typing_extensions':
+            self.__module__ = def_mod
+
+
+# Python 3.10+ has PEP 612
+if hasattr(typing, 'ParamSpecArgs'):
+    ParamSpecArgs = typing.ParamSpecArgs
+    ParamSpecKwargs = typing.ParamSpecKwargs
+# 3.7-3.9
+else:
+    class _Immutable:
+        """Mixin to indicate that object should not be copied."""
+        __slots__ = ()
+
+        def __copy__(self):
+            return self
+
+        def __deepcopy__(self, memo):
+            return self
+
+    class ParamSpecArgs(_Immutable):
+        """The args for a ParamSpec object.
+
+        Given a ParamSpec object P, P.args is an instance of ParamSpecArgs.
+
+        ParamSpecArgs objects have a reference back to their ParamSpec:
+
+        P.args.__origin__ is P
+
+        This type is meant for runtime introspection and has no special meaning to
+        static type checkers.
+        """
+        def __init__(self, origin):
+            self.__origin__ = origin
+
+        def __repr__(self):
+            return f"{self.__origin__.__name__}.args"
+
+        def __eq__(self, other):
+            if not isinstance(other, ParamSpecArgs):
+                return NotImplemented
+            return self.__origin__ == other.__origin__
+
+    class ParamSpecKwargs(_Immutable):
+        """The kwargs for a ParamSpec object.
+
+        Given a ParamSpec object P, P.kwargs is an instance of ParamSpecKwargs.
+
+        ParamSpecKwargs objects have a reference back to their ParamSpec:
+
+        P.kwargs.__origin__ is P
+
+        This type is meant for runtime introspection and has no special meaning to
+        static type checkers.
+        """
+        def __init__(self, origin):
+            self.__origin__ = origin
+
+        def __repr__(self):
+            return f"{self.__origin__.__name__}.kwargs"
+
+        def __eq__(self, other):
+            if not isinstance(other, ParamSpecKwargs):
+                return NotImplemented
+            return self.__origin__ == other.__origin__
+
+# 3.10+
+if hasattr(typing, 'ParamSpec'):
+
+    # Add default Parameter - PEP 696
+    class ParamSpec(typing.ParamSpec, _DefaultMixin, _root=True):
+        """Parameter specification variable."""
+
+        __module__ = 'typing'
+
+        def __init__(self, name, *, bound=None, covariant=False, contravariant=False,
+                     default=None):
+            super().__init__(name, bound=bound, covariant=covariant,
+                             contravariant=contravariant)
+            _DefaultMixin.__init__(self, default)
+
+            # for pickling:
+            try:
+                def_mod = sys._getframe(1).f_globals.get('__name__', '__main__')
+            except (AttributeError, ValueError):
+                def_mod = None
+            if def_mod != 'typing_extensions':
+                self.__module__ = def_mod
+
+# 3.7-3.9
+else:
+
+    # Inherits from list as a workaround for Callable checks in Python < 3.9.2.
+    class ParamSpec(list, _DefaultMixin):
+        """Parameter specification variable.
+
+        Usage::
+
+           P = ParamSpec('P')
+
+        Parameter specification variables exist primarily for the benefit of static
+        type checkers.  They are used to forward the parameter types of one
+        callable to another callable, a pattern commonly found in higher order
+        functions and decorators.  They are only valid when used in ``Concatenate``,
+        or s the first argument to ``Callable``. In Python 3.10 and higher,
+        they are also supported in user-defined Generics at runtime.
+        See class Generic for more information on generic types.  An
+        example for annotating a decorator::
+
+           T = TypeVar('T')
+           P = ParamSpec('P')
+
+           def add_logging(f: Callable[P, T]) -> Callable[P, T]:
+               '''A type-safe decorator to add logging to a function.'''
+               def inner(*args: P.args, **kwargs: P.kwargs) -> T:
+                   logging.info(f'{f.__name__} was called')
+                   return f(*args, **kwargs)
+               return inner
+
+           @add_logging
+           def add_two(x: float, y: float) -> float:
+               '''Add two numbers together.'''
+               return x + y
+
+        Parameter specification variables defined with covariant=True or
+        contravariant=True can be used to declare covariant or contravariant
+        generic types.  These keyword arguments are valid, but their actual semantics
+        are yet to be decided.  See PEP 612 for details.
+
+        Parameter specification variables can be introspected. e.g.:
+
+           P.__name__ == 'T'
+           P.__bound__ == None
+           P.__covariant__ == False
+           P.__contravariant__ == False
+
+        Note that only parameter specification variables defined in global scope can
+        be pickled.
+        """
+
+        # Trick Generic __parameters__.
+        __class__ = typing.TypeVar
+
+        @property
+        def args(self):
+            return ParamSpecArgs(self)
+
+        @property
+        def kwargs(self):
+            return ParamSpecKwargs(self)
+
+        def __init__(self, name, *, bound=None, covariant=False, contravariant=False,
+                     default=None):
+            super().__init__([self])
+            self.__name__ = name
+            self.__covariant__ = bool(covariant)
+            self.__contravariant__ = bool(contravariant)
+            if bound:
+                self.__bound__ = typing._type_check(bound, 'Bound must be a type.')
+            else:
+                self.__bound__ = None
+            _DefaultMixin.__init__(self, default)
+
+            # for pickling:
+            try:
+                def_mod = sys._getframe(1).f_globals.get('__name__', '__main__')
+            except (AttributeError, ValueError):
+                def_mod = None
+            if def_mod != 'typing_extensions':
+                self.__module__ = def_mod
+
+        def __repr__(self):
+            if self.__covariant__:
+                prefix = '+'
+            elif self.__contravariant__:
+                prefix = '-'
+            else:
+                prefix = '~'
+            return prefix + self.__name__
+
+        def __hash__(self):
+            return object.__hash__(self)
+
+        def __eq__(self, other):
+            return self is other
+
+        def __reduce__(self):
+            return self.__name__
+
+        # Hack to get typing._type_check to pass.
+        def __call__(self, *args, **kwargs):
+            pass
+
+
+# 3.7-3.9
+if not hasattr(typing, 'Concatenate'):
+    # Inherits from list as a workaround for Callable checks in Python < 3.9.2.
+    class _ConcatenateGenericAlias(list):
+
+        # Trick Generic into looking into this for __parameters__.
+        __class__ = typing._GenericAlias
+
+        # Flag in 3.8.
+        _special = False
+
+        def __init__(self, origin, args):
+            super().__init__(args)
+            self.__origin__ = origin
+            self.__args__ = args
+
+        def __repr__(self):
+            _type_repr = typing._type_repr
+            return (f'{_type_repr(self.__origin__)}'
+                    f'[{", ".join(_type_repr(arg) for arg in self.__args__)}]')
+
+        def __hash__(self):
+            return hash((self.__origin__, self.__args__))
+
+        # Hack to get typing._type_check to pass in Generic.
+        def __call__(self, *args, **kwargs):
+            pass
+
+        @property
+        def __parameters__(self):
+            return tuple(
+                tp for tp in self.__args__ if isinstance(tp, (typing.TypeVar, ParamSpec))
+            )
+
+
+# 3.7-3.9
+@typing._tp_cache
+def _concatenate_getitem(self, parameters):
+    if parameters == ():
+        raise TypeError("Cannot take a Concatenate of no types.")
+    if not isinstance(parameters, tuple):
+        parameters = (parameters,)
+    if not isinstance(parameters[-1], ParamSpec):
+        raise TypeError("The last parameter to Concatenate should be a "
+                        "ParamSpec variable.")
+    msg = "Concatenate[arg, ...]: each arg must be a type."
+    parameters = tuple(typing._type_check(p, msg) for p in parameters)
+    return _ConcatenateGenericAlias(self, parameters)
+
+
+# 3.10+
+if hasattr(typing, 'Concatenate'):
+    Concatenate = typing.Concatenate
+    _ConcatenateGenericAlias = typing._ConcatenateGenericAlias # noqa
+# 3.9
+elif sys.version_info[:2] >= (3, 9):
+    @_TypeAliasForm
+    def Concatenate(self, parameters):
+        """Used in conjunction with ``ParamSpec`` and ``Callable`` to represent a
+        higher order function which adds, removes or transforms parameters of a
+        callable.
+
+        For example::
+
+           Callable[Concatenate[int, P], int]
+
+        See PEP 612 for detailed information.
+        """
+        return _concatenate_getitem(self, parameters)
+# 3.7-8
+else:
+    class _ConcatenateForm(typing._SpecialForm, _root=True):
+        def __repr__(self):
+            return 'typing_extensions.' + self._name
+
+        def __getitem__(self, parameters):
+            return _concatenate_getitem(self, parameters)
+
+    Concatenate = _ConcatenateForm(
+        'Concatenate',
+        doc="""Used in conjunction with ``ParamSpec`` and ``Callable`` to represent a
+        higher order function which adds, removes or transforms parameters of a
+        callable.
+
+        For example::
+
+           Callable[Concatenate[int, P], int]
+
+        See PEP 612 for detailed information.
+        """)
+
+# 3.10+
+if hasattr(typing, 'TypeGuard'):
+    TypeGuard = typing.TypeGuard
+# 3.9
+elif sys.version_info[:2] >= (3, 9):
+    class _TypeGuardForm(typing._SpecialForm, _root=True):
+        def __repr__(self):
+            return 'typing_extensions.' + self._name
+
+    @_TypeGuardForm
+    def TypeGuard(self, parameters):
+        """Special typing form used to annotate the return type of a user-defined
+        type guard function.  ``TypeGuard`` only accepts a single type argument.
+        At runtime, functions marked this way should return a boolean.
+
+        ``TypeGuard`` aims to benefit *type narrowing* -- a technique used by static
+        type checkers to determine a more precise type of an expression within a
+        program's code flow.  Usually type narrowing is done by analyzing
+        conditional code flow and applying the narrowing to a block of code.  The
+        conditional expression here is sometimes referred to as a "type guard".
+
+        Sometimes it would be convenient to use a user-defined boolean function
+        as a type guard.  Such a function should use ``TypeGuard[...]`` as its
+        return type to alert static type checkers to this intention.
+
+        Using  ``-> TypeGuard`` tells the static type checker that for a given
+        function:
+
+        1. The return value is a boolean.
+        2. If the return value is ``True``, the type of its argument
+        is the type inside ``TypeGuard``.
+
+        For example::
+
+            def is_str(val: Union[str, float]):
+                # "isinstance" type guard
+                if isinstance(val, str):
+                    # Type of ``val`` is narrowed to ``str``
+                    ...
+                else:
+                    # Else, type of ``val`` is narrowed to ``float``.
+                    ...
+
+        Strict type narrowing is not enforced -- ``TypeB`` need not be a narrower
+        form of ``TypeA`` (it can even be a wider form) and this may lead to
+        type-unsafe results.  The main reason is to allow for things like
+        narrowing ``List[object]`` to ``List[str]`` even though the latter is not
+        a subtype of the former, since ``List`` is invariant.  The responsibility of
+        writing type-safe type guards is left to the user.
+
+        ``TypeGuard`` also works with type variables.  For more information, see
+        PEP 647 (User-Defined Type Guards).
+        """
+        item = typing._type_check(parameters, f'{self} accepts only a single type.')
+        return typing._GenericAlias(self, (item,))
+# 3.7-3.8
+else:
+    class _TypeGuardForm(typing._SpecialForm, _root=True):
+
+        def __repr__(self):
+            return 'typing_extensions.' + self._name
+
+        def __getitem__(self, parameters):
+            item = typing._type_check(parameters,
+                                      f'{self._name} accepts only a single type')
+            return typing._GenericAlias(self, (item,))
+
+    TypeGuard = _TypeGuardForm(
+        'TypeGuard',
+        doc="""Special typing form used to annotate the return type of a user-defined
+        type guard function.  ``TypeGuard`` only accepts a single type argument.
+        At runtime, functions marked this way should return a boolean.
+
+        ``TypeGuard`` aims to benefit *type narrowing* -- a technique used by static
+        type checkers to determine a more precise type of an expression within a
+        program's code flow.  Usually type narrowing is done by analyzing
+        conditional code flow and applying the narrowing to a block of code.  The
+        conditional expression here is sometimes referred to as a "type guard".
+
+        Sometimes it would be convenient to use a user-defined boolean function
+        as a type guard.  Such a function should use ``TypeGuard[...]`` as its
+        return type to alert static type checkers to this intention.
+
+        Using  ``-> TypeGuard`` tells the static type checker that for a given
+        function:
+
+        1. The return value is a boolean.
+        2. If the return value is ``True``, the type of its argument
+        is the type inside ``TypeGuard``.
+
+        For example::
+
+            def is_str(val: Union[str, float]):
+                # "isinstance" type guard
+                if isinstance(val, str):
+                    # Type of ``val`` is narrowed to ``str``
+                    ...
+                else:
+                    # Else, type of ``val`` is narrowed to ``float``.
+                    ...
+
+        Strict type narrowing is not enforced -- ``TypeB`` need not be a narrower
+        form of ``TypeA`` (it can even be a wider form) and this may lead to
+        type-unsafe results.  The main reason is to allow for things like
+        narrowing ``List[object]`` to ``List[str]`` even though the latter is not
+        a subtype of the former, since ``List`` is invariant.  The responsibility of
+        writing type-safe type guards is left to the user.
+
+        ``TypeGuard`` also works with type variables.  For more information, see
+        PEP 647 (User-Defined Type Guards).
+        """)
+
+
+# Vendored from cpython typing._SpecialFrom
+class _SpecialForm(typing._Final, _root=True):
+    __slots__ = ('_name', '__doc__', '_getitem')
+
+    def __init__(self, getitem):
+        self._getitem = getitem
+        self._name = getitem.__name__
+        self.__doc__ = getitem.__doc__
+
+    def __getattr__(self, item):
+        if item in {'__name__', '__qualname__'}:
+            return self._name
+
+        raise AttributeError(item)
+
+    def __mro_entries__(self, bases):
+        raise TypeError(f"Cannot subclass {self!r}")
+
+    def __repr__(self):
+        return f'typing_extensions.{self._name}'
+
+    def __reduce__(self):
+        return self._name
+
+    def __call__(self, *args, **kwds):
+        raise TypeError(f"Cannot instantiate {self!r}")
+
+    def __or__(self, other):
+        return typing.Union[self, other]
+
+    def __ror__(self, other):
+        return typing.Union[other, self]
+
+    def __instancecheck__(self, obj):
+        raise TypeError(f"{self} cannot be used with isinstance()")
+
+    def __subclasscheck__(self, cls):
+        raise TypeError(f"{self} cannot be used with issubclass()")
+
+    @typing._tp_cache
+    def __getitem__(self, parameters):
+        return self._getitem(self, parameters)
+
+
+if hasattr(typing, "LiteralString"):
+    LiteralString = typing.LiteralString
+else:
+    @_SpecialForm
+    def LiteralString(self, params):
+        """Represents an arbitrary literal string.
+
+        Example::
+
+          from typing_extensions import LiteralString
+
+          def query(sql: LiteralString) -> ...:
+              ...
+
+          query("SELECT * FROM table")  # ok
+          query(f"SELECT * FROM {input()}")  # not ok
+
+        See PEP 675 for details.
+
+        """
+        raise TypeError(f"{self} is not subscriptable")
+
+
+if hasattr(typing, "Self"):
+    Self = typing.Self
+else:
+    @_SpecialForm
+    def Self(self, params):
+        """Used to spell the type of "self" in classes.
+
+        Example::
+
+          from typing import Self
+
+          class ReturnsSelf:
+              def parse(self, data: bytes) -> Self:
+                  ...
+                  return self
+
+        """
+
+        raise TypeError(f"{self} is not subscriptable")
+
+
+if hasattr(typing, "Never"):
+    Never = typing.Never
+else:
+    @_SpecialForm
+    def Never(self, params):
+        """The bottom type, a type that has no members.
+
+        This can be used to define a function that should never be
+        called, or a function that never returns::
+
+            from typing_extensions import Never
+
+            def never_call_me(arg: Never) -> None:
+                pass
+
+            def int_or_str(arg: int | str) -> None:
+                never_call_me(arg)  # type checker error
+                match arg:
+                    case int():
+                        print("It's an int")
+                    case str():
+                        print("It's a str")
+                    case _:
+                        never_call_me(arg)  # ok, arg is of type Never
+
+        """
+
+        raise TypeError(f"{self} is not subscriptable")
+
+
+if hasattr(typing, 'Required'):
+    Required = typing.Required
+    NotRequired = typing.NotRequired
+elif sys.version_info[:2] >= (3, 9):
+    class _ExtensionsSpecialForm(typing._SpecialForm, _root=True):
+        def __repr__(self):
+            return 'typing_extensions.' + self._name
+
+    @_ExtensionsSpecialForm
+    def Required(self, parameters):
+        """A special typing construct to mark a key of a total=False TypedDict
+        as required. For example:
+
+            class Movie(TypedDict, total=False):
+                title: Required[str]
+                year: int
+
+            m = Movie(
+                title='The Matrix',  # typechecker error if key is omitted
+                year=1999,
+            )
+
+        There is no runtime checking that a required key is actually provided
+        when instantiating a related TypedDict.
+        """
+        item = typing._type_check(parameters, f'{self._name} accepts only a single type.')
+        return typing._GenericAlias(self, (item,))
+
+    @_ExtensionsSpecialForm
+    def NotRequired(self, parameters):
+        """A special typing construct to mark a key of a TypedDict as
+        potentially missing. For example:
+
+            class Movie(TypedDict):
+                title: str
+                year: NotRequired[int]
+
+            m = Movie(
+                title='The Matrix',  # typechecker error if key is omitted
+                year=1999,
+            )
+        """
+        item = typing._type_check(parameters, f'{self._name} accepts only a single type.')
+        return typing._GenericAlias(self, (item,))
+
+else:
+    class _RequiredForm(typing._SpecialForm, _root=True):
+        def __repr__(self):
+            return 'typing_extensions.' + self._name
+
+        def __getitem__(self, parameters):
+            item = typing._type_check(parameters,
+                                      f'{self._name} accepts only a single type.')
+            return typing._GenericAlias(self, (item,))
+
+    Required = _RequiredForm(
+        'Required',
+        doc="""A special typing construct to mark a key of a total=False TypedDict
+        as required. For example:
+
+            class Movie(TypedDict, total=False):
+                title: Required[str]
+                year: int
+
+            m = Movie(
+                title='The Matrix',  # typechecker error if key is omitted
+                year=1999,
+            )
+
+        There is no runtime checking that a required key is actually provided
+        when instantiating a related TypedDict.
+        """)
+    NotRequired = _RequiredForm(
+        'NotRequired',
+        doc="""A special typing construct to mark a key of a TypedDict as
+        potentially missing. For example:
+
+            class Movie(TypedDict):
+                title: str
+                year: NotRequired[int]
+
+            m = Movie(
+                title='The Matrix',  # typechecker error if key is omitted
+                year=1999,
+            )
+        """)
+
+
+if hasattr(typing, "Unpack"):  # 3.11+
+    Unpack = typing.Unpack
+elif sys.version_info[:2] >= (3, 9):
+    class _UnpackSpecialForm(typing._SpecialForm, _root=True):
+        def __repr__(self):
+            return 'typing_extensions.' + self._name
+
+    class _UnpackAlias(typing._GenericAlias, _root=True):
+        __class__ = typing.TypeVar
+
+    @_UnpackSpecialForm
+    def Unpack(self, parameters):
+        """A special typing construct to unpack a variadic type. For example:
+
+            Shape = TypeVarTuple('Shape')
+            Batch = NewType('Batch', int)
+
+            def add_batch_axis(
+                x: Array[Unpack[Shape]]
+            ) -> Array[Batch, Unpack[Shape]]: ...
+
+        """
+        item = typing._type_check(parameters, f'{self._name} accepts only a single type.')
+        return _UnpackAlias(self, (item,))
+
+    def _is_unpack(obj):
+        return isinstance(obj, _UnpackAlias)
+
+else:
+    class _UnpackAlias(typing._GenericAlias, _root=True):
+        __class__ = typing.TypeVar
+
+    class _UnpackForm(typing._SpecialForm, _root=True):
+        def __repr__(self):
+            return 'typing_extensions.' + self._name
+
+        def __getitem__(self, parameters):
+            item = typing._type_check(parameters,
+                                      f'{self._name} accepts only a single type.')
+            return _UnpackAlias(self, (item,))
+
+    Unpack = _UnpackForm(
+        'Unpack',
+        doc="""A special typing construct to unpack a variadic type. For example:
+
+            Shape = TypeVarTuple('Shape')
+            Batch = NewType('Batch', int)
+
+            def add_batch_axis(
+                x: Array[Unpack[Shape]]
+            ) -> Array[Batch, Unpack[Shape]]: ...
+
+        """)
+
+    def _is_unpack(obj):
+        return isinstance(obj, _UnpackAlias)
+
+
+if hasattr(typing, "TypeVarTuple"):  # 3.11+
+
+    # Add default Parameter - PEP 696
+    class TypeVarTuple(typing.TypeVarTuple, _DefaultMixin, _root=True):
+        """Type variable tuple."""
+
+        def __init__(self, name, *, default=None):
+            super().__init__(name)
+            _DefaultMixin.__init__(self, default)
+
+            # for pickling:
+            try:
+                def_mod = sys._getframe(1).f_globals.get('__name__', '__main__')
+            except (AttributeError, ValueError):
+                def_mod = None
+            if def_mod != 'typing_extensions':
+                self.__module__ = def_mod
+
+else:
+    class TypeVarTuple(_DefaultMixin):
+        """Type variable tuple.
+
+        Usage::
+
+            Ts = TypeVarTuple('Ts')
+
+        In the same way that a normal type variable is a stand-in for a single
+        type such as ``int``, a type variable *tuple* is a stand-in for a *tuple*
+        type such as ``Tuple[int, str]``.
+
+        Type variable tuples can be used in ``Generic`` declarations.
+        Consider the following example::
+
+            class Array(Generic[*Ts]): ...
+
+        The ``Ts`` type variable tuple here behaves like ``tuple[T1, T2]``,
+        where ``T1`` and ``T2`` are type variables. To use these type variables
+        as type parameters of ``Array``, we must *unpack* the type variable tuple using
+        the star operator: ``*Ts``. The signature of ``Array`` then behaves
+        as if we had simply written ``class Array(Generic[T1, T2]): ...``.
+        In contrast to ``Generic[T1, T2]``, however, ``Generic[*Shape]`` allows
+        us to parameterise the class with an *arbitrary* number of type parameters.
+
+        Type variable tuples can be used anywhere a normal ``TypeVar`` can.
+        This includes class definitions, as shown above, as well as function
+        signatures and variable annotations::
+
+            class Array(Generic[*Ts]):
+
+                def __init__(self, shape: Tuple[*Ts]):
+                    self._shape: Tuple[*Ts] = shape
+
+                def get_shape(self) -> Tuple[*Ts]:
+                    return self._shape
+
+            shape = (Height(480), Width(640))
+            x: Array[Height, Width] = Array(shape)
+            y = abs(x)  # Inferred type is Array[Height, Width]
+            z = x + x   #        ...    is Array[Height, Width]
+            x.get_shape()  #     ...    is tuple[Height, Width]
+
+        """
+
+        # Trick Generic __parameters__.
+        __class__ = typing.TypeVar
+
+        def __iter__(self):
+            yield self.__unpacked__
+
+        def __init__(self, name, *, default=None):
+            self.__name__ = name
+            _DefaultMixin.__init__(self, default)
+
+            # for pickling:
+            try:
+                def_mod = sys._getframe(1).f_globals.get('__name__', '__main__')
+            except (AttributeError, ValueError):
+                def_mod = None
+            if def_mod != 'typing_extensions':
+                self.__module__ = def_mod
+
+            self.__unpacked__ = Unpack[self]
+
+        def __repr__(self):
+            return self.__name__
+
+        def __hash__(self):
+            return object.__hash__(self)
+
+        def __eq__(self, other):
+            return self is other
+
+        def __reduce__(self):
+            return self.__name__
+
+        def __init_subclass__(self, *args, **kwds):
+            if '_root' not in kwds:
+                raise TypeError("Cannot subclass special typing classes")
+
+
+if hasattr(typing, "reveal_type"):
+    reveal_type = typing.reveal_type
+else:
+    def reveal_type(__obj: T) -> T:
+        """Reveal the inferred type of a variable.
+
+        When a static type checker encounters a call to ``reveal_type()``,
+        it will emit the inferred type of the argument::
+
+            x: int = 1
+            reveal_type(x)
+
+        Running a static type checker (e.g., ``mypy``) on this example
+        will produce output similar to 'Revealed type is "builtins.int"'.
+
+        At runtime, the function prints the runtime type of the
+        argument and returns it unchanged.
+
+        """
+        print(f"Runtime type is {type(__obj).__name__!r}", file=sys.stderr)
+        return __obj
+
+
+if hasattr(typing, "assert_never"):
+    assert_never = typing.assert_never
+else:
+    def assert_never(__arg: Never) -> Never:
+        """Assert to the type checker that a line of code is unreachable.
+
+        Example::
+
+            def int_or_str(arg: int | str) -> None:
+                match arg:
+                    case int():
+                        print("It's an int")
+                    case str():
+                        print("It's a str")
+                    case _:
+                        assert_never(arg)
+
+        If a type checker finds that a call to assert_never() is
+        reachable, it will emit an error.
+
+        At runtime, this throws an exception when called.
+
+        """
+        raise AssertionError("Expected code to be unreachable")
+
+
+if hasattr(typing, 'dataclass_transform'):
+    dataclass_transform = typing.dataclass_transform
+else:
+    def dataclass_transform(
+        *,
+        eq_default: bool = True,
+        order_default: bool = False,
+        kw_only_default: bool = False,
+        field_specifiers: typing.Tuple[
+            typing.Union[typing.Type[typing.Any], typing.Callable[..., typing.Any]],
+            ...
+        ] = (),
+        **kwargs: typing.Any,
+    ) -> typing.Callable[[T], T]:
+        """Decorator that marks a function, class, or metaclass as providing
+        dataclass-like behavior.
+
+        Example:
+
+            from typing_extensions import dataclass_transform
+
+            _T = TypeVar("_T")
+
+            # Used on a decorator function
+            @dataclass_transform()
+            def create_model(cls: type[_T]) -> type[_T]:
+                ...
+                return cls
+
+            @create_model
+            class CustomerModel:
+                id: int
+                name: str
+
+            # Used on a base class
+            @dataclass_transform()
+            class ModelBase: ...
+
+            class CustomerModel(ModelBase):
+                id: int
+                name: str
+
+            # Used on a metaclass
+            @dataclass_transform()
+            class ModelMeta(type): ...
+
+            class ModelBase(metaclass=ModelMeta): ...
+
+            class CustomerModel(ModelBase):
+                id: int
+                name: str
+
+        Each of the ``CustomerModel`` classes defined in this example will now
+        behave similarly to a dataclass created with the ``@dataclasses.dataclass``
+        decorator. For example, the type checker will synthesize an ``__init__``
+        method.
+
+        The arguments to this decorator can be used to customize this behavior:
+        - ``eq_default`` indicates whether the ``eq`` parameter is assumed to be
+          True or False if it is omitted by the caller.
+        - ``order_default`` indicates whether the ``order`` parameter is
+          assumed to be True or False if it is omitted by the caller.
+        - ``kw_only_default`` indicates whether the ``kw_only`` parameter is
+          assumed to be True or False if it is omitted by the caller.
+        - ``field_specifiers`` specifies a static list of supported classes
+          or functions that describe fields, similar to ``dataclasses.field()``.
+
+        At runtime, this decorator records its arguments in the
+        ``__dataclass_transform__`` attribute on the decorated object.
+
+        See PEP 681 for details.
+
+        """
+        def decorator(cls_or_fn):
+            cls_or_fn.__dataclass_transform__ = {
+                "eq_default": eq_default,
+                "order_default": order_default,
+                "kw_only_default": kw_only_default,
+                "field_specifiers": field_specifiers,
+                "kwargs": kwargs,
+            }
+            return cls_or_fn
+        return decorator
+
+
+if hasattr(typing, "override"):
+    override = typing.override
+else:
+    _F = typing.TypeVar("_F", bound=typing.Callable[..., typing.Any])
+
+    def override(__arg: _F) -> _F:
+        """Indicate that a method is intended to override a method in a base class.
+
+        Usage:
+
+            class Base:
+                def method(self) -> None: ...
+                    pass
+
+            class Child(Base):
+                @override
+                def method(self) -> None:
+                    super().method()
+
+        When this decorator is applied to a method, the type checker will
+        validate that it overrides a method with the same name on a base class.
+        This helps prevent bugs that may occur when a base class is changed
+        without an equivalent change to a child class.
+
+        See PEP 698 for details.
+
+        """
+        return __arg
+
+
+# We have to do some monkey patching to deal with the dual nature of
+# Unpack/TypeVarTuple:
+# - We want Unpack to be a kind of TypeVar so it gets accepted in
+#   Generic[Unpack[Ts]]
+# - We want it to *not* be treated as a TypeVar for the purposes of
+#   counting generic parameters, so that when we subscript a generic,
+#   the runtime doesn't try to substitute the Unpack with the subscripted type.
+if not hasattr(typing, "TypeVarTuple"):
+    typing._collect_type_vars = _collect_type_vars
+    typing._check_generic = _check_generic
+
+
+# Backport typing.NamedTuple as it exists in Python 3.11.
+# In 3.11, the ability to define generic `NamedTuple`s was supported.
+# This was explicitly disallowed in 3.9-3.10, and only half-worked in <=3.8.
+if sys.version_info >= (3, 11):
+    NamedTuple = typing.NamedTuple
+else:
+    def _caller():
+        try:
+            return sys._getframe(2).f_globals.get('__name__', '__main__')
+        except (AttributeError, ValueError):  # For platforms without _getframe()
+            return None
+
+    def _make_nmtuple(name, types, module, defaults=()):
+        fields = [n for n, t in types]
+        annotations = {n: typing._type_check(t, f"field {n} annotation must be a type")
+                       for n, t in types}
+        nm_tpl = collections.namedtuple(name, fields,
+                                        defaults=defaults, module=module)
+        nm_tpl.__annotations__ = nm_tpl.__new__.__annotations__ = annotations
+        # The `_field_types` attribute was removed in 3.9;
+        # in earlier versions, it is the same as the `__annotations__` attribute
+        if sys.version_info < (3, 9):
+            nm_tpl._field_types = annotations
+        return nm_tpl
+
+    _prohibited_namedtuple_fields = typing._prohibited
+    _special_namedtuple_fields = frozenset({'__module__', '__name__', '__annotations__'})
+
+    class _NamedTupleMeta(type):
+        def __new__(cls, typename, bases, ns):
+            assert _NamedTuple in bases
+            for base in bases:
+                if base is not _NamedTuple and base is not typing.Generic:
+                    raise TypeError(
+                        'can only inherit from a NamedTuple type and Generic')
+            bases = tuple(tuple if base is _NamedTuple else base for base in bases)
+            types = ns.get('__annotations__', {})
+            default_names = []
+            for field_name in types:
+                if field_name in ns:
+                    default_names.append(field_name)
+                elif default_names:
+                    raise TypeError(f"Non-default namedtuple field {field_name} "
+                                    f"cannot follow default field"
+                                    f"{'s' if len(default_names) > 1 else ''} "
+                                    f"{', '.join(default_names)}")
+            nm_tpl = _make_nmtuple(
+                typename, types.items(),
+                defaults=[ns[n] for n in default_names],
+                module=ns['__module__']
+            )
+            nm_tpl.__bases__ = bases
+            if typing.Generic in bases:
+                class_getitem = typing.Generic.__class_getitem__.__func__
+                nm_tpl.__class_getitem__ = classmethod(class_getitem)
+            # update from user namespace without overriding special namedtuple attributes
+            for key in ns:
+                if key in _prohibited_namedtuple_fields:
+                    raise AttributeError("Cannot overwrite NamedTuple attribute " + key)
+                elif key not in _special_namedtuple_fields and key not in nm_tpl._fields:
+                    setattr(nm_tpl, key, ns[key])
+            if typing.Generic in bases:
+                nm_tpl.__init_subclass__()
+            return nm_tpl
+
+    def NamedTuple(__typename, __fields=None, **kwargs):
+        if __fields is None:
+            __fields = kwargs.items()
+        elif kwargs:
+            raise TypeError("Either list of fields or keywords"
+                            " can be provided to NamedTuple, not both")
+        return _make_nmtuple(__typename, __fields, module=_caller())
+
+    NamedTuple.__doc__ = typing.NamedTuple.__doc__
+    _NamedTuple = type.__new__(_NamedTupleMeta, 'NamedTuple', (), {})
+
+    # On 3.8+, alter the signature so that it matches typing.NamedTuple.
+    # The signature of typing.NamedTuple on >=3.8 is invalid syntax in Python 3.7,
+    # so just leave the signature as it is on 3.7.
+    if sys.version_info >= (3, 8):
+        NamedTuple.__text_signature__ = '(typename, fields=None, /, **kwargs)'
+
+    def _namedtuple_mro_entries(bases):
+        assert NamedTuple in bases
+        return (_NamedTuple,)
+
+    NamedTuple.__mro_entries__ = _namedtuple_mro_entries
diff --git a/third_party/python/setuptools/pkg_resources/_vendor/zipp.py b/third_party/python/setuptools/pkg_resources/_vendor/zipp.py
new file mode 100644
index 0000000000..26b723c1fd
--- /dev/null
+++ b/third_party/python/setuptools/pkg_resources/_vendor/zipp.py
@@ -0,0 +1,329 @@
+import io
+import posixpath
+import zipfile
+import itertools
+import contextlib
+import sys
+import pathlib
+
+if sys.version_info < (3, 7):
+    from collections import OrderedDict
+else:
+    OrderedDict = dict
+
+
+__all__ = ['Path']
+
+
+def _parents(path):
+    """
+    Given a path with elements separated by
+    posixpath.sep, generate all parents of that path.
+
+    >>> list(_parents('b/d'))
+    ['b']
+    >>> list(_parents('/b/d/'))
+    ['/b']
+    >>> list(_parents('b/d/f/'))
+    ['b/d', 'b']
+    >>> list(_parents('b'))
+    []
+    >>> list(_parents(''))
+    []
+    """
+    return itertools.islice(_ancestry(path), 1, None)
+
+
+def _ancestry(path):
+    """
+    Given a path with elements separated by
+    posixpath.sep, generate all elements of that path
+
+    >>> list(_ancestry('b/d'))
+    ['b/d', 'b']
+    >>> list(_ancestry('/b/d/'))
+    ['/b/d', '/b']
+    >>> list(_ancestry('b/d/f/'))
+    ['b/d/f', 'b/d', 'b']
+    >>> list(_ancestry('b'))
+    ['b']
+    >>> list(_ancestry(''))
+    []
+    """
+    path = path.rstrip(posixpath.sep)
+    while path and path != posixpath.sep:
+        yield path
+        path, tail = posixpath.split(path)
+
+
+_dedupe = OrderedDict.fromkeys
+"""Deduplicate an iterable in original order"""
+
+
+def _difference(minuend, subtrahend):
+    """
+    Return items in minuend not in subtrahend, retaining order
+    with O(1) lookup.
+    """
+    return itertools.filterfalse(set(subtrahend).__contains__, minuend)
+
+
+class CompleteDirs(zipfile.ZipFile):
+    """
+    A ZipFile subclass that ensures that implied directories
+    are always included in the namelist.
+    """
+
+    @staticmethod
+    def _implied_dirs(names):
+        parents = itertools.chain.from_iterable(map(_parents, names))
+        as_dirs = (p + posixpath.sep for p in parents)
+        return _dedupe(_difference(as_dirs, names))
+
+    def namelist(self):
+        names = super(CompleteDirs, self).namelist()
+        return names + list(self._implied_dirs(names))
+
+    def _name_set(self):
+        return set(self.namelist())
+
+    def resolve_dir(self, name):
+        """
+        If the name represents a directory, return that name
+        as a directory (with the trailing slash).
+        """
+        names = self._name_set()
+        dirname = name + '/'
+        dir_match = name not in names and dirname in names
+        return dirname if dir_match else name
+
+    @classmethod
+    def make(cls, source):
+        """
+        Given a source (filename or zipfile), return an
+        appropriate CompleteDirs subclass.
+        """
+        if isinstance(source, CompleteDirs):
+            return source
+
+        if not isinstance(source, zipfile.ZipFile):
+            return cls(_pathlib_compat(source))
+
+        # Only allow for FastLookup when supplied zipfile is read-only
+        if 'r' not in source.mode:
+            cls = CompleteDirs
+
+        source.__class__ = cls
+        return source
+
+
+class FastLookup(CompleteDirs):
+    """
+    ZipFile subclass to ensure implicit
+    dirs exist and are resolved rapidly.
+    """
+
+    def namelist(self):
+        with contextlib.suppress(AttributeError):
+            return self.__names
+        self.__names = super(FastLookup, self).namelist()
+        return self.__names
+
+    def _name_set(self):
+        with contextlib.suppress(AttributeError):
+            return self.__lookup
+        self.__lookup = super(FastLookup, self)._name_set()
+        return self.__lookup
+
+
+def _pathlib_compat(path):
+    """
+    For path-like objects, convert to a filename for compatibility
+    on Python 3.6.1 and earlier.
+    """
+    try:
+        return path.__fspath__()
+    except AttributeError:
+        return str(path)
+
+
+class Path:
+    """
+    A pathlib-compatible interface for zip files.
+
+    Consider a zip file with this structure::
+
+        .
+        ├── a.txt
+        └── b
+            ├── c.txt
+            └── d
+                └── e.txt
+
+    >>> data = io.BytesIO()
+    >>> zf = zipfile.ZipFile(data, 'w')
+    >>> zf.writestr('a.txt', 'content of a')
+    >>> zf.writestr('b/c.txt', 'content of c')
+    >>> zf.writestr('b/d/e.txt', 'content of e')
+    >>> zf.filename = 'mem/abcde.zip'
+
+    Path accepts the zipfile object itself or a filename
+
+    >>> root = Path(zf)
+
+    From there, several path operations are available.
+
+    Directory iteration (including the zip file itself):
+
+    >>> a, b = root.iterdir()
+    >>> a
+    Path('mem/abcde.zip', 'a.txt')
+    >>> b
+    Path('mem/abcde.zip', 'b/')
+
+    name property:
+
+    >>> b.name
+    'b'
+
+    join with divide operator:
+
+    >>> c = b / 'c.txt'
+    >>> c
+    Path('mem/abcde.zip', 'b/c.txt')
+    >>> c.name
+    'c.txt'
+
+    Read text:
+
+    >>> c.read_text()
+    'content of c'
+
+    existence:
+
+    >>> c.exists()
+    True
+    >>> (b / 'missing.txt').exists()
+    False
+
+    Coercion to string:
+
+    >>> import os
+    >>> str(c).replace(os.sep, posixpath.sep)
+    'mem/abcde.zip/b/c.txt'
+
+    At the root, ``name``, ``filename``, and ``parent``
+    resolve to the zipfile. Note these attributes are not
+    valid and will raise a ``ValueError`` if the zipfile
+    has no filename.
+
+    >>> root.name
+    'abcde.zip'
+    >>> str(root.filename).replace(os.sep, posixpath.sep)
+    'mem/abcde.zip'
+    >>> str(root.parent)
+    'mem'
+    """
+
+    __repr = "{self.__class__.__name__}({self.root.filename!r}, {self.at!r})"
+
+    def __init__(self, root, at=""):
+        """
+        Construct a Path from a ZipFile or filename.
+
+        Note: When the source is an existing ZipFile object,
+        its type (__class__) will be mutated to a
+        specialized type. If the caller wishes to retain the
+        original type, the caller should either create a
+        separate ZipFile object or pass a filename.
+        """
+        self.root = FastLookup.make(root)
+        self.at = at
+
+    def open(self, mode='r', *args, pwd=None, **kwargs):
+        """
+        Open this entry as text or binary following the semantics
+        of ``pathlib.Path.open()`` by passing arguments through
+        to io.TextIOWrapper().
+        """
+        if self.is_dir():
+            raise IsADirectoryError(self)
+        zip_mode = mode[0]
+        if not self.exists() and zip_mode == 'r':
+            raise FileNotFoundError(self)
+        stream = self.root.open(self.at, zip_mode, pwd=pwd)
+        if 'b' in mode:
+            if args or kwargs:
+                raise ValueError("encoding args invalid for binary operation")
+            return stream
+        return io.TextIOWrapper(stream, *args, **kwargs)
+
+    @property
+    def name(self):
+        return pathlib.Path(self.at).name or self.filename.name
+
+    @property
+    def suffix(self):
+        return pathlib.Path(self.at).suffix or self.filename.suffix
+
+    @property
+    def suffixes(self):
+        return pathlib.Path(self.at).suffixes or self.filename.suffixes
+
+    @property
+    def stem(self):
+        return pathlib.Path(self.at).stem or self.filename.stem
+
+    @property
+    def filename(self):
+        return pathlib.Path(self.root.filename).joinpath(self.at)
+
+    def read_text(self, *args, **kwargs):
+        with self.open('r', *args, **kwargs) as strm:
+            return strm.read()
+
+    def read_bytes(self):
+        with self.open('rb') as strm:
+            return strm.read()
+
+    def _is_child(self, path):
+        return posixpath.dirname(path.at.rstrip("/")) == self.at.rstrip("/")
+
+    def _next(self, at):
+        return self.__class__(self.root, at)
+
+    def is_dir(self):
+        return not self.at or self.at.endswith("/")
+
+    def is_file(self):
+        return self.exists() and not self.is_dir()
+
+    def exists(self):
+        return self.at in self.root._name_set()
+
+    def iterdir(self):
+        if not self.is_dir():
+            raise ValueError("Can't listdir a file")
+        subs = map(self._next, self.root.namelist())
+        return filter(self._is_child, subs)
+
+    def __str__(self):
+        return posixpath.join(self.root.filename, self.at)
+
+    def __repr__(self):
+        return self.__repr.format(self=self)
+
+    def joinpath(self, *other):
+        next = posixpath.join(self.at, *map(_pathlib_compat, other))
+        return self._next(self.root.resolve_dir(next))
+
+    __truediv__ = joinpath
+
+    @property
+    def parent(self):
+        if not self.at:
+            return self.filename.parent
+        parent_at = posixpath.dirname(self.at.rstrip('/'))
+        if parent_at:
+            parent_at += '/'
+        return self._next(parent_at)
diff --git a/third_party/python/setuptools/pkg_resources/extern/__init__.py b/third_party/python/setuptools/pkg_resources/extern/__init__.py
new file mode 100644
index 0000000000..948bcc6094
--- /dev/null
+++ b/third_party/python/setuptools/pkg_resources/extern/__init__.py
@@ -0,0 +1,80 @@
+import importlib.util
+import sys
+
+
+class VendorImporter:
+    """
+    A PEP 302 meta path importer for finding optionally-vendored
+    or otherwise naturally-installed packages from root_name.
+    """
+
+    def __init__(self, root_name, vendored_names=(), vendor_pkg=None):
+        self.root_name = root_name
+        self.vendored_names = set(vendored_names)
+        self.vendor_pkg = vendor_pkg or root_name.replace('extern', '_vendor')
+
+    @property
+    def search_path(self):
+        """
+        Search first the vendor package then as a natural package.
+        """
+        yield self.vendor_pkg + '.'
+        yield ''
+
+    def _module_matches_namespace(self, fullname):
+        """Figure out if the target module is vendored."""
+        root, base, target = fullname.partition(self.root_name + '.')
+        return not root and any(map(target.startswith, self.vendored_names))
+
+    def load_module(self, fullname):
+        """
+        Iterate over the search path to locate and load fullname.
+        """
+        root, base, target = fullname.partition(self.root_name + '.')
+        for prefix in self.search_path:
+            try:
+                extant = prefix + target
+                __import__(extant)
+                mod = sys.modules[extant]
+                sys.modules[fullname] = mod
+                return mod
+            except ImportError:
+                pass
+        else:
+            raise ImportError(
+                "The '{target}' package is required; "
+                "normally this is bundled with this package so if you get "
+                "this warning, consult the packager of your "
+                "distribution.".format(**locals())
+            )
+
+    def create_module(self, spec):
+        return self.load_module(spec.name)
+
+    def exec_module(self, module):
+        pass
+
+    def find_spec(self, fullname, path=None, target=None):
+        """Return a module spec for vendored names."""
+        return (
+            importlib.util.spec_from_loader(fullname, self)
+            if self._module_matches_namespace(fullname)
+            else None
+        )
+
+    def install(self):
+        """
+        Install this importer into sys.meta_path if not already present.
+        """
+        if self not in sys.meta_path:
+            sys.meta_path.append(self)
+
+
+names = (
+    'packaging',
+    'platformdirs',
+    'jaraco',
+    'importlib_resources',
+    'more_itertools',
+)
+VendorImporter(__name__, names).install()