1 files changed, 22 insertions, 0 deletions
diff --git a/third_party/python/taskcluster_taskgraph/taskgraph/util/readonlydict.py b/third_party/python/taskcluster_taskgraph/taskgraph/util/readonlydict.py
new file mode 100644
index 0000000000..55d74f479a
--- /dev/null
+++ b/third_party/python/taskcluster_taskgraph/taskgraph/util/readonlydict.py
@@ -0,0 +1,22 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this file,
+# You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# Imported from
+# https://searchfox.org/mozilla-central/rev/c3ebaf6de2d481c262c04bb9657eaf76bf47e2ac/python/mozbuild/mozbuild/util.py#115-127
+
+
+class ReadOnlyDict(dict):
+    """A read-only dictionary."""
+
+    def __init__(self, *args, **kwargs):
+        dict.__init__(self, *args, **kwargs)
+
+    def __delitem__(self, key):
+        raise Exception("Object does not support deletion.")
+
+    def __setitem__(self, key, value):
+        raise Exception("Object does not support assignment.")
+
+    def update(self, *args, **kwargs):
+        raise Exception("Object does not support update.")