<gml:Surface xmlns:gml="http://www.opengis.net/gml" srsName="foo">
    <gml:patches>
        <gml:PolygonPatch interpolation="planar">
            <gml:exterior>
                <gml:LinearRing>
                    <gml:posList>1 2 3 4 5 6 1 2</gml:posList>
                </gml:LinearRing>
            </gml:exterior>
            <gml:interior>
                <gml:LinearRing>
                    <gml:posList>2 3 4 5 6 7 2 3</gml:posList>
                </gml:LinearRing>
            </gml:interior>    
            <gml:interior>
                <gml:LinearRing>
                    <gml:posList>3 4 5 6 7 8 3 4</gml:posList>
                </gml:LinearRing>
            </gml:interior>
        </gml:PolygonPatch>
    </gml:patches>
</gml:Surface>
