/**
  * Analyze referral code and get parent for the customer.
  *
  * @param int $customerId
  * @param int $parentId
  * @return int
  */
 public function getReferredParentId($customerId, $parentId)
 {
     /* use customer ID as parent ID if parent ID is missed */
     $result = $parentId ? $parentId : $customerId;
     $code = $this->_toolReferral->getReferralCode();
     if ($code) {
         $parentDo = $this->_repoCustomer->getByReferralCode($code);
         if ($parentDo) {
             $result = $parentDo->getCustomerId();
         }
     }
     return $result;
 }