code: protected function throwUnsupportedAction($operation, $reason = null)
      {
          throw new ShipmentGatewayException(sprintf(
              "The shipment gateway '%s' does not support '%s' operation. %s",
              $this->getName(), $operation, $reason
          ));
      }
docs: Throws an unsupported operation exception.
  
  @param string $operation
  @param string $reason
  
  @throws ShipmentGatewayException