Consider the following:

>>> it = iter(range(2**32 + 2))
>>> for _ in range(2**32):
...   _ = next(it)
>>> it2 = pickle.loads(
...   pickle.dumps(it)
... )
>>> assert next(it) == next(it2)

This assert currently fails because the reduce method for range iterator objects serializes to `int` instead of `long`.

(note that running this example might take tens of minutes on your box)