This allows enums to be type check with mypy.
They will still behave like ints ->
> IntEnum is the same as Enum,
> but its members are also integers and can be used anywhere
> that an integer can be used.
> If any integer operation is performed with an IntEnum member,
> the resulting value loses its enumeration status.
https://docs.python.org/3/library/enum.html#enum.IntEnum
Only if the --python-typing flag is set.