<afx-app-window apptitle="Image Editor" width="600" height="600" data-id="ImageEditor">
    <afx-hbox>
        <div data-width="2"></div>
        <afx-vbox>
            <div data-id="stage"></div>
            <div data-height="2"></div>
        </afx-vbox>
        <div data-width="2"></div>
    </afx-hbox>
</afx-app-window>