<virtualType name="SectionInvalidationConfigReader"
             type="Magento\Framework\Config\Reader\Filesystem">
    <arguments>
        <argument name="idAttributes" xsi:type="array">
            <item name="/config/action" xsi:type="string">
                name
            </item>
            <item name="/config/action/section" xsi:type="string">
                name
            </item>
        </argument>
        <argument name="fileName" xsi:type="string">
            sections.xml
        </argument>
        <argument name="converter" xsi:type="object">
            \Magento\Customer\CustomerData\SectionConfigConverter
        </argument>
        <argument name="schemaLocator" xsi:type="object">
            Magento\Customer\CustomerData\SchemaLocator
        </argument>
        <argument name="defaultScope" xsi:type="string">
            frontend
        </argument>
    </arguments>
</virtualType>

This is a virtual type configuration.

This configuration is for the base area. Base area configurations will apply to all the sub-applications.

This virtualType configuration tells the Object Manager when a user wants a virtual SectionInvalidationConfigReader object that it should return a Magento\Framework\Config\Reader\Filesystem object.

This configuration tells the Object Manager that when a user wants a SectionInvalidationConfigReader object that the following arguments should be used in the foo object's constructor.

• $idAttributes = [...items...];
• $fileName = "sections.xml";
• $converter = new \Magento\Customer\CustomerData\SectionConfigConverter (...)
• $schemaLocator = new Magento\Customer\CustomerData\SchemaLocator (...)
• $defaultScope = "frontend";