Issue #22609: Constructor of collections.UserDict now accepts the self keyword

argument.

diff --cc Lib/collections/__init__.py
Simple merge

diff --cc Lib/test/test_userdict.py
Simple merge

diff --cc Misc/NEWS
index 08b20b9ff182c34bf069d4d6f29f1b6d71e6a9de,3a9ddda0552a9f7bf0acfcaf7db1f51abb40dbc3..c56bb1582fd9ae02ba0590e630e90e6c6f7eb406
--- 1/Misc/NEWS
--- 2/Misc/NEWS
+++ b/Misc/NEWS
@@@ -21,8 -78,9 +21,11 @@@ Core and Builtin
  Library
  -------
  
+ - Issue #22609: Constructor of collections.UserDict now accepts the self keyword
+   argument.
+ 
 +- Issue #25111: Fixed comparison of traceback.FrameSummary.
 +
  - Issue #25262. Added support for BINBYTES8 opcode in Python implementation of
    unpickler.  Highest 32 bits of 64-bit size for BINUNICODE8 and BINBYTES8
    opcodes no longer silently ignored on 32-bit platforms in C implementation.