NamespaceSupport namespaces = new NamespaceSupport();
namespaces.declarePrefix("gml", GML.NAMESPACE);
namespaces.declarePrefix("xmml", XMMLNS);
FilterFactory2 ff = new FilterFactoryImplNamespaceAware(namespaces);
PropertyIsEqualTo complexFilter = ff.equals(ff.property("gml:name"), ff
.literal("SWADLINCOTE"));
visitor = new UnmappingFilterVisitor(mapping);
Filter unrolled = (Filter) complexFilter.accept(visitor, null);