Fix TypeIs negative narrowing of union of generics - #18193

Fix TypeIs negative narrowing of union of generics#18193

hauntsaninja merged 7 commits into

python:masterpython/mypy:masterfrom

brianschubert:gh-18009-typeis-union-genericbrianschubert/mypy:gh-18009-typeis-union-genericCopy head branch name to clipboard