Original file line numberDiff line numberDiff line change@@ -45,6 +45,11 @@
4545else:
4646_collections_abc.MutableSequence.register(deque)
474748+try:
49+from_collectionsimport_deque_iterator
50+exceptImportError:
51+pass
52+4853try:
4954from_collectionsimportdefaultdict
5055exceptImportError: