[issue31033] Add argument to .cancel() of Task and Future

[Yury Selivanov]

Yury Selivanov <yselivanov at gmail.com> added the comment:

Elevating to release blocker to make sure it's included. The PR is good.

----------

_______________________________________
Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue31033>
_______________________________________