magento-test/app/code/Magento/Customer/Test/Mftf/ActionGroup/AdminAssertDefaultBillingAddressToggleIsOnOnAddUpdateAddressPageActionGroup.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="AdminAssertDefaultBillingAddressToggleIsOnOnAddUpdateAddressPageActionGroup">
        <annotations>
            <description>Asserts that the "Default Billing Address" toggle is On on the Add/Update Address Sliding Tab of Customer Edit Page </description>
        </annotations>
        
        <assertElementContainsAttribute stepKey="assertDefaultBillingIsEnabledOnAddUpdateAddressTab">
			<expectedResult selector="{{AdminCustomerAddressesSection.defaultBillingAddressCheckBox}}" attribute="value" type="string">1</expectedResult>
        </assertElementContainsAttribute>
    </actionGroup>
</actionGroups>