public function aroundExecute(
        \Temando\Shipping\Observer\SaveCheckoutFieldsObserver $subject,
        \Closure $proceed,
        \Magento\Framework\Event\Observer $observer
    ) {
        /** @var \Magento\Quote\Api\Data\AddressInterface|\Magento\Quote\Model\Quote\Address $quoteAddress */
        $quoteAddress = $observer->getData('quote_address');
        if ($quoteAddress->getAddressType() !== \Magento\Quote\Model\Quote\Address::ADDRESS_TYPE_SHIPPING) {
            return;
        }

        if (!$quoteAddress->getExtensionAttributes()) {
            return;
        }

        if (!$quoteAddress->getExtensionAttributes()->getCheckoutFields()) {
            return;
        }

        $proceed($observer);
    }