def forward(self, tensor_1: torch.Tensor, tensor_2: torch.Tensor) -> torch.Tensor:
        # pylint: disable=arguments-differ
        """
        Takes two tensors of the same shape, such as ``(batch_size, length_1, length_2,
        embedding_dim)``.  Computes a (possibly parameterized) similarity on the final dimension
        and returns a tensor with one less dimension, such as ``(batch_size, length_1, length_2)``.
        """
        raise NotImplementedError