/**
  * Returns the order referrer id
  *
  * @return integer
  */
 protected function getReferrerId()
 {
     // Sub-objects
     $Partner = $this->Order->getPartner();
     // Referrer
     if ($Partner) {
         try {
             $referrerId = PlentymarketsMappingController::getReferrerByShopwareID($Partner->getId());
         } catch (PlentymarketsMappingExceptionNotExistant $E) {
         }
     }
     return isset($referrerId) ? $referrerId : PlentymarketsConfig::getInstance()->getOrderReferrerID();
 }