plugins/devkit/testData/pluginXmlDomStubs/pluginWithXInclude.xml

<idea-plugin version="2">

    <id>foo</id>

    <extensionPoints>
        <extensionPoint name="bar"/>
    </extensionPoints>

    <extensions defaultExtensionNs="foo">

        <bar/>
        <extension/>
    </extensions>

</idea-plugin>