Context
find_one_and_update's existing type hint makes the false claim that the method returns a _DocumentType. However, the docstring (correctly) tells us that the method "Returns ``None`` if no document matches the filter."
The same is true of other find_one_and_* methods.
Definition of done
A PR has been submitted by Cal Jacobson (cj81499). We have reviewed. This issue is here for posterity and to follow our new PR template process.