Operation opDescriptor = new Operation("", serviceDesc, null, new Object[] { gfreq });
final GeoServer gs = wms.getGeoServer();
FeatureTypeSchemaBuilder sb = new FeatureTypeSchemaBuilder.GML3(gs);
WFSConfiguration configuration = new WFSConfiguration(gs, sb, new WFS(sb));
GML3OutputFormat format = new GML3OutputFormat(gs, configuration);
format.write(features, out, opDescriptor);
}