magento-test/app/code/Magento/Customer/Test/Mftf/ActionGroup/StorefrontSignOutActionGroup.xml

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

<actionGroups xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
              xsi:noNamespaceSchemaLocation="urn:magento:mftf:Test/etc/actionGroupSchema.xsd">
    <actionGroup name="StorefrontSignOutActionGroup">
        <annotations>
            <description>Clicks on Customer Account. Clicks on 'Sign-Out'. Validates that the success message is present and correct. PLEASE NOTE: The Success Message is hardcoded.</description>
        </annotations>

        <click selector="{{StoreFrontSignOutSection.customerAccount}}" stepKey="clickCustomerButton"/>
        <click selector="{{StoreFrontSignOutSection.signOut}}" stepKey="clickToSignOut"/>
        <waitForPageLoad stepKey="waitForPageLoad"/>
        <waitForText userInput="You are signed out" stepKey="signOut"/>
    </actionGroup>
</actionGroups>