Hi. Thanks for the PR :)

However, I fear that if we want to add type hinting, it should be done for everything at once. I.e. maybe not in a single PR, but at least we should work on a dedicated branch and then merge to master. Therefore, I'll be closing this for now.

If you feel like starting on adding type hinting for the entire library (you are very welcome!), I suggest to comment on #1373 to make sure we're in sync on how we approach this.