A few comments between imports were removed or moved to the top of the
import block, due to behavioral differences between black and isort. See
psf/black#251 for details.
In two instances @overloads at the top of the file needed to be moved
due to psf/black#1490.
See https://bugs.python.org/issue32689.
This bug only affects `src`s which are directory
Paths in Python 3.5 to 3.8 inclusive.
Comes at the cost of restricting
`src` to str even where a Path would work but
this might be preferable to exposing the bug.
* Drop support for Python 3.3
* Merge Python 2 and 3 shutil
* Marked some arguments optional
* Changed callback return type from None to Any for more flexibility
