code: def get_combined_dim(combination: str, tensor_dims: List[int]) -> int:
      
      if len(tensor_dims) > 9:
          raise ConfigurationError("Double-digit tensor lists not currently supported")
      combination = combination.replace('x', '1').replace('y', '2')
      return sum([_get_combination_dim(piece, tensor_dims) for piece in combination.split(',')])
docs: For use with :func:`combine_tensors`.  This function computes the resultant dimension when
      calling ``combine_tensors(combination, tensors)``, when the tensor dimension is known.  This is
      necessary for knowing the sizes of weight matrices when building models that use
      ``combine_tensors``.
  
      Parameters
      ----------
      combination : ``str``
          A comma-separated list of combination pieces, like ``"1,2,1*2"``, specified identically to
          ``combination`` in :func:`combine_tensors`.
      tensor_dims : ``List[int]``
          A list of tensor dimensions, where each dimension is from the `last axis` of the tensors
          that will be input to :func:`combine_tensors`.