Ticket #2261: base.py.patch

base.py

@@ -77 +77 @@
     def __eq__(self, other):
         return isinstance(other, self.__class__) and self._get_pk_val() == other._get_pk_val()
 
+    def __hash__(self):
+        return hash('%s%s' % (hash(self.__class__), self._get_pk_val()))
+
     def __ne__(self, other):
         return not self.__eq__(other)