BasketBuilderNew::setItemData

public function setItemData($basketCode, &$productData, &$item)
{
	//Let's extract cached provider product data from field
	if(!empty($productData["PROVIDER_DATA"]) && CheckSerializedData($productData["PROVIDER_DATA"]))
	{
		if($providerData = unserialize($productData["PROVIDER_DATA"], ['allowed_classes' => false]))
		{
			$this->builder->sendProductCachedDataToProvider($item, $this->builder->getOrder(), $providerData);
		}
	}

	if(!empty($productData["SET_ITEMS_DATA"]) && CheckSerializedData($productData["SET_ITEMS_DATA"]))
	{
		$productData["SET_ITEMS"] = unserialize($productData["SET_ITEMS_DATA"], ['allowed_classes' => false]);
	}

	$res = $item->setField("QUANTITY", $item->getField("QUANTITY")+$productData["QUANTITY"]);

	if(!$res->isSuccess())
	{
		$this->builder->getErrorsContainer()->addErrors($res->getErrors());
		throw  new BuildingException();
	}
}