Trim21

@GalaxySnail any review?

CI is broken

> > CI is broken > > Yes. (That's what tests intend to do.) We should fix them before merging. no... As I mentioned before, you only need to run...

> > no... As I mentioned before, you only need to run mypy's stubtest in latest python, no need to run it in old python version. > > I doubt...

> > and ci failed because you try to run mypy in old version of python, mypy need python>=3.6. it has nothing to do with type stub. > > OK,...

> > > OK, thanks for your clarification. So we should run mypy on python>=3.6 only. AFAIK the latest version of mypy which supports python2 is mypy 0.971 [1]. >...

> > > > OK, thanks for your clarification. So we should run mypy on python>=3.6 only. AFAIK the latest version of mypy which supports python2 is mypy 0.971 [1]....

Sorry, the test you added failed ci's python2.7 testing job, I don't know how to fix it.

> Thank you both all the attention and efforts and concerns. I understand that python 2 compatibility is difficult, especially for typing. > > I have created Issue #102 with...

@ishchenko looks like this issue has been fixed， do you mind make a new release？