public void write(WMSMapContext mapContext, OutputStream output) throws Exception {
List features = new ArrayList();
for (int i = 0; i < mapContext.getLayerCount(); i++) {
MapLayer l = mapContext.getLayer(i);
if (l.toLayer() instanceof FeatureLayer) {
FeatureSource source = mapContext.getLayer(i).getFeatureSource();
features.add(source.getFeatures(l.getQuery()));
}
}