/**
  * Returns the customer class id
  *
  * @return integer|null
  */
 protected function getCustomerClassId()
 {
     try {
         return PlentymarketsMappingController::getCustomerClassByShopwareID($this->Customer->getGroup()->getId());
     } catch (Exception $E) {
         PyLog()->debug($E->getMessage());
         return null;
     }
 }