cartExtensionFactory = $cartExtensionFactory; $this->quoteLinkFactory = $quoteLinkFactory; } /** * {@inheritDoc} */ public function setAmazonOrderReferenceIdExtensionAttribute(CartInterface $cart) { $cartExtension = ($cart->getExtensionAttributes()) ?: $this->cartExtensionFactory->create(); $amazonQuote = $this->quoteLinkFactory->create(); $amazonQuote->load($cart->getId(), 'quote_id'); if ($amazonQuote->getId()) { $cartExtension->setAmazonOrderReferenceId($amazonQuote); } $cart->setExtensionAttributes($cartExtension); } }