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