@lindsay-stevens I used nose2 instead of nose (as mentioned in the README) to run tests and everything was fine (the same in pyCharm). I did that because I had problems with using nose which is no longer maintained.
It looks like the old nose does not recognize str | None: I'm I right?

I recommend using the dev requirements as-is and using a supported Python version. In addition to the readme, the GitHub workflows show how to set up a dev environment from scratch.

The union operator for types was added in Python 3.10 (docs) as an alternative to Union[X, Y]. For the Union[str, None] case, it can (perhaps more clearly) be written as Optional[str, None]. Not related to the nose package.

The union operator for types was added in Python 3.10 (docs) as an alternative to Union[X, Y]. For the Union[str, None] case, it can (perhaps more clearly) be written as Optional[str, None]. Not related to the nose package.

Right. It's fixed.

@grzesiek2010 not sure if you're waiting on me but there are a few comments from the last review to address. Thanks

@grzesiek2010 not sure if you're waiting on me but there are a few comments from the last review to address. Thanks

ups what exactly? I think I've addressed all of them. I've responded to all your comments with Done/Fixed and it's reflected in my commits.

@grzesiek2010 I thought you could see the comments because you responded to the one about the Union operator. I have tagged you in the remaining ones. Thanks

Thanks @grzesiek2010 ! @lognaturel I think the PR is ready to merge - do you want this in master or some other branch?

We’re going to master now! Can’t wait to get all the good stuff there released. 🚀