bpo-23722: Raise a RuntimeError for absent classcell. (GH-6931)

A DeprecationWarning was emitted in Python 3.6-3.7.

Serhiy Storchaka committed 8y ago

f5e7b1999f46e592d42dfab51563ea5411946fb7

Parent: 8ae8e6a

Committed by GitHub <noreply@github.com> on 5/20/2018, 5:48:12 AM

bpo-23722: Raise a RuntimeError for absent __classcell__. (GH-6931)