/**
  * @param $name
  * @param $amountOfSeats
  * @param null $amountOfWheelChairs
  * @param integer $sortOrder
  * @param null $memo
  * @return VehicleCategory
  */
 public static function registerVehicleCategory($name, $amountOfSeats, $amountOfWheelChairs = null, $sortOrder = 0, $memo = null)
 {
     $vehicleCategory = new VehicleCategory();
     $vehicleCategory->setName($name);
     $vehicleCategory->setMemo($memo);
     $vehicleCategory->setAmountOfSeats($amountOfSeats);
     $amountOfWheelChairs = null !== $amountOfWheelChairs ? $amountOfWheelChairs : 0;
     $vehicleCategory->setAmountOfWheelChairs($amountOfWheelChairs);
     $vehicleCategory->setSortOrder($sortOrder);
     return $vehicleCategory;
 }