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# 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.
from __future__ import absolute_import, division, print_function
import sys
from ._typing import TYPE_CHECKING
if TYPE_CHECKING: # pragma: no cover
from typing import Any, Dict, Tuple, Type
PY2 = sys.version_info[0] == 2
PY3 = sys.version_info[0] == 3
# flake8: noqa
if PY3:
string_types = (str,)
else:
string_types = (basestring,)
def with_metaclass(meta, *bases):
# type: (Type[Any], Tuple[Type[Any], ...]) -> Any
"""
Create a base class with a metaclass.
"""
# This requires a bit of explanation: the basic idea is to make a dummy
# metaclass for one level of class instantiation that replaces itself with
# the actual metaclass.
class metaclass(meta): # type: ignore
def __new__(cls, name, this_bases, d):
# type: (Type[Any], str, Tuple[Any], Dict[Any, Any]) -> Any
return meta(name, bases, d)
return type.__new__(metaclass, "temporary_class", (), {})
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