Fix failure to detect that iterators have special casing
@@ -368,6 +368,7 @@ def is_reducible(obj):
is_sequence_subclass(obj) or
is_function(obj) or
is_module(obj) or
+ is_iterator(obj) or
type(getattr(obj, '__slots__', None)) is IteratorType or
type(obj) is object or
obj is object or
