public function merge(\Ess\M2ePro\Model\Order\Item\Proxy $that) { $this->setQty($this->getQty() + $that->getOriginalQty()); $this->subtotal += $that->getOriginalPrice() * $that->getOriginalQty(); // merge additional data // --------------------------------------- $thisAdditionalData = $this->getAdditionalData(); $thatAdditionalData = $that->getAdditionalData(); $identifier = \Ess\M2ePro\Helper\Data::CUSTOM_IDENTIFIER; $thisAdditionalData[$identifier]['items'][] = $thatAdditionalData[$identifier]['items'][0]; $this->additionalData = $thisAdditionalData; // --------------------------------------- }