code: def _rapply(input_layer, operation, *op_args, **op_kwargs):
    
    op_args = list(op_args)
    op_args.append(input_layer.tensor)
    return input_layer.with_tensor(operation(*op_args, **op_kwargs))
docs: Applies the given operation to this after expanding op_args.
  
    Args:
      input_layer: The input layer for this op.
      operation: An operation that takes a tensor and the supplied args.
      *op_args: Extra arguments for operation.
      **op_kwargs: Keyword arguments for the operation.
    Returns:
      A new layer with operation applied.