magento-test/app/code/Magento/Checkout/Test/Mftf/Page/CheckoutPage.xml

<?xml version="1.0" encoding="UTF-8"?>
<!--
 /**
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
-->

<pages xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:noNamespaceSchemaLocation="urn:magento:mftf:Page/etc/PageObject.xsd">
    <page name="CheckoutPage" url="/checkout" area="storefront" module="Magento_Checkout">
        <section name="StorefrontCheckoutPageMessagesSection"/>
        <section name="CheckoutShippingSection"/>
        <section name="CheckoutShippingMethodsSection"/>
        <section name="CheckoutOrderSummarySection"/>
        <section name="CheckoutSuccessMainSection"/>
        <section name="CheckoutPaymentSection"/>
        <section name="SelectShippingBillingPopupSection"/>
    </page>
</pages>