issue_comments: 1137623370

I have encountered another problem that is related to this: DataArray.argmins dim argument is: Hashable | Sequence[Hashable] | None, where None is a special case that will apply over all dimensions.

So I tried to overload this: ```python @overload def argmin( self, dim: Hashable, *, axis: int | None = None, keep_attrs: bool | None = None, skipna: bool | None = None, ) -> DataArray: ...

@overload
def argmin(
    self,
    dim: Sequence[Hashable] | None = None,
    axis: int | None = None,
    keep_attrs: bool | None = None,
    skipna: bool | None = None,
) -> dict[Hashable, DataArray]:
    ...

``` but mypy complains:

Overloaded function signatures 1 and 2 overlap with incompatible return types [misc]

I suspect that this is due to the fact that None is actually Hashable and therefore a valid dimension.

Unfortunately, using this proposal of str | Sequence[Hashable] won't work since str is actually a Sequence of Hashables... (I know that this proposal is meant for functions that always expect multiple dims and the str is only a lazy mans shortcut)