Add removal of dict.setdefault()

pep-3000.txt

@@ -125,6 +125,7 @@ To be removed:
 * ``basestring.find()`` and ``basestring.rfind()``; use ``basestring.index()``
   or ``basestring.rindex()`` in a try/except block [15]_
 * ``file.xreadlines()`` method [17]_
+* ``dict.setdefault()`` [22]_
 
 
 Standard library
@@ -231,6 +232,9 @@ References
 .. [21] python-dev email 
    http://mail.python.org/pipermail/python-dev/2006-February/061169.html
 
+.. [22] python-dev email ("defaultdict")
+   http://mail.python.org/pipermail/python-dev/2006-February/061261.html
+
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