Fix __hash__ in functools.cmp_to_key() to work with collections.Hashable.
diff --git a/Lib/functools.py b/Lib/functools.py
index e92a2fc..90642a5 100644
--- a/Lib/functools.py
+++ b/Lib/functools.py
@@ -111,8 +111,7 @@
             return mycmp(self.obj, other.obj) >= 0
         def __ne__(self, other):
             return mycmp(self.obj, other.obj) != 0
-        def __hash__(self):
-            raise TypeError('hash not implemented')
+        __hash__ = None
     return K
 
 _CacheInfo = namedtuple("CacheInfo", "hits misses maxsize currsize")