[3.5] bpo-15718: Document the upper bound constrain on the __len__ re…#1260

serhiy-storchaka merged 1 commit into

python:3.5python/cpython:3.5from

serhiy-storchaka:backport-85157cd-3.5serhiy-storchaka/cpython:backport-85157cd-3.5Copy head branch name to clipboard