CustomAttributeList.php

<?php
/**
 * Copyright © Magento, Inc. All rights reserved.
 * See COPYING.txt for license details.
 */
namespace Magento\Quote\Model\Quote\Address;

class CustomAttributeList implements CustomAttributeListInterface
{
    /**
     * Retrieve list of quote address custom attributes
     *
     * @return array
     */
    public function getAttributes()
    {
        return [];
    }
}