code: def _safe_sparse_mask(tensor: torch.Tensor, mask: torch.Tensor) -> torch.Tensor:
      
      # pylint: disable=protected-access
      try:
          return tensor.sparse_mask(mask)
      except AttributeError:
          # TODO(joelgrus): remove this and/or warn at some point
          return tensor._sparse_mask(mask)
docs: In PyTorch 1.0, Tensor._sparse_mask was changed to Tensor.sparse_mask.
      This wrapper allows AllenNLP to (temporarily) work with both 1.0 and 0.4.1.