/**
  * @param \Orm\Zed\Sales\Persistence\SpySalesOrder $orderEntity
  *
  * @return array
  */
 protected function getVoucherCodes(SpySalesOrder $orderEntity)
 {
     $voucherCodes = [];
     foreach ($orderEntity->getDiscounts() as $discountEntity) {
         foreach ($discountEntity->getDiscountCodes() as $salesDiscountCodesEntity) {
             $voucherCodes[$salesDiscountCodesEntity->getCode()] = $salesDiscountCodesEntity->getCode();
         }
     }
     return $voucherCodes;
 }