Better test for BytesIO.__sizeof__, now that the struct module supports (s)size_t. Followup to issue #15489.
Better test for BytesIO.__sizeof__, now that the struct module supports (s)size_t.
Followup to issue #15489.

sk-/python2.7-type-annotator,sk-/python2.7-type-annotator,sk-/python2.7-type-annotator