Let the world know that UserList is a MutableSequence.
diff --git a/Lib/UserList.py b/Lib/UserList.py
index 116122f..348ea76 100644
--- a/Lib/UserList.py
+++ b/Lib/UserList.py
@@ -1,6 +1,8 @@
"""A more or less complete user-defined wrapper around list objects."""
-class UserList:
+import collections
+
+class UserList(collections.MutableSequence):
def __init__(self, initlist=None):
self.data = []
if initlist is not None:
@@ -69,3 +71,5 @@
self.data.extend(other.data)
else:
self.data.extend(other)
+
+collections.MutableSequence.register(UserList)