xstream.alias("version", Version.class);
xstream.addImmutableType(Version.class);
xstream.registerConverter(new VersionConverter());
// URI
xstream.alias("uri", URI.class);
xstream.addImmutableType(URI.class);
xstream.registerConverter(new URIConverter());
// XStreamGBeanState
xstream.registerConverter(new XStreamGBeanStateConverter());