bpo-44490: Improve typing module compatibility with types.Union by uriyyo · Pull Request #27048 · python/cpython

Yurii, sorry for the delay. Was a little busy. This LGTM. Thanks for submitting this PR.

BTW, it looks like the C changes to types.Union in the other PR won't make to 3.10 (we missed the beta 4 deadline). So we don't have to worry about backporting anymore.