code: private function getItemType($mode)
      {
          switch ($mode) {
              case self::ITEM_TYPE_ID_VOUCHER:
                  return OrderItem::TYPE_VOUCHER;
              case self::ITEM_TYPE_ID_DISCOUNT:
                  return OrderItem::TYPE_DISCOUNT;
              case self::ITEM_TYPE_ID_SURCHARGE:
                  if (json_decode($this->configService->get('surcharge_as_product'), false)) {
                      return OrderItem::TYPE_PRODUCT;
                  }
  
                  return OrderItem::TYPE_PAYMENT_SURCHARGE;
              default:
                  return OrderItem::TYPE_PRODUCT;
          }
      }
docs: @param int $mode
  
  @return int