/**
  * add the sku for the chosen gift wrapping
  * @param  IGifting
  * @param  Varien_Object
  * @return self
  */
 protected function _addGiftWrapItem(IGifting $giftingPayload, Varien_Object $giftingItem)
 {
     $giftWrapId = $giftingItem->getGwId();
     if ($giftWrapId) {
         $giftwrap = Mage::getModel('enterprise_giftwrapping/wrapping')->load($giftWrapId);
         $giftingPayload->setGiftItemId($giftwrap->getEb2cSku())->setIncludeGiftWrapping(true);
         $this->_getPriceGroup($giftingPayload)->setTaxClass($giftwrap->getEb2cTaxClass());
     }
     return $this;
 }