Made MultiValueDict.__deepcopy__()'s memo kwarg an arg.
It's always provided.
@@ -91,9 +91,7 @@ class MultiValueDict(dict):
for k, v in self.lists()
])
- def __deepcopy__(self, memo=None):
- if memo is None:
- memo = {}
+ def __deepcopy__(self, memo):
result = self.__class__()
memo[id(self)] = result
for key, value in dict.items(self):
