Mark Xiong

- looks like after fixing the we we build objects and those errors, mypy is not working as expected as it detects some errors in files I didn't even modify....

> Let's take a look at the errors for the non generated files: > > ``` > api/reviews_api.py:60: error: Item "None" of "GetVotesResponse | None" has no attribute "to_dict" [union-attr]...

Regarding the mypy errors in generated files, I found this PR of openapi-generator which already solved the bug: https://github.com/OpenAPITools/openapi-generator/pull/19223. Should we update our tool to the latest release? @jcscottiii