/**
* Add AvaTax specific extension attribute fields to a \Magento\Tax\Model\Sales\Quote\ItemDetails object
*
* @param \Magento\Tax\Api\Data\QuoteDetailsItemInterface $quoteDetailsItem
* @param $avaTaxItemCode
* @param $avaTaxTaxCode
* @param $avaTaxDescription
* @return $this
*/
protected function addExtensionAttributesToTaxQuoteDetailsItem(\Magento\Tax\Api\Data\QuoteDetailsItemInterface $quoteDetailsItem, $avaTaxItemCode, $avaTaxTaxCode, $avaTaxDescription)
{
/** @var \Magento\Tax\Api\Data\QuoteDetailsItemExtensionInterface $extensionAttribute */
$extensionAttribute = $quoteDetailsItem->getExtensionAttributes() ? $quoteDetailsItem->getExtensionAttributes() : $this->extensionFactory->create();
$extensionAttribute->setAvataxItemCode($avaTaxItemCode);
$extensionAttribute->setAvataxTaxCode($avaTaxTaxCode);
$extensionAttribute->setAvataxDescription($avaTaxDescription);
$quoteDetailsItem->setExtensionAttributes($extensionAttribute);
return $this;
}