Mypy error error: Name 'torch.cuda.DoubleTensor' is not defined

I am trying to create a python dataclass that supports both cpu and gpu DoubleTensor:

class SomeDC:
    element: Union[torch.DoubleTensor, torch.cuda.DoubleTensor]

However, this results in the mypy error error: Name 'torch.cuda.DoubleTensor' is not defined. I tried import torch.cuda but the same error occurs. Anyone know if there is a workaround for this or do I just ignore this mypy error?

Note, the code runs fine this way, the only problem is the mypy error.