bpo-32996: Documentation fix-up. (GH-16646)


PR GH-4906 changed the typing.Generic class hierarchy, leaving an
outdated comment in the library reference. User-defined Generic ABCs now
must get a abc.ABCMeta metaclass from something other than typing.Generic
inheritance.
(cherry picked from commit d47f0dd2e85ce032aebfedbde18cdb2e728fa79f)

Co-authored-by: M. Eric Irrgang <mei2n@virginia.edu>
1 file changed