The astimezone() correctness proof endured much pain to prove what turned out to be 3 special cases of a single more-general result. Proving the latter instead is a real simplification.
The astimezone() correctness proof endured much pain to prove what
turned out to be 3 special cases of a single more-general result.
Proving the latter instead is a real simplification.

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