TransitionAnchor(Navigation navigation, final Class<P> toPage, final Multimap<String, String> state) {
this.navigation = Assert.notNull(navigation);
this.toPageWidgetType = Assert.notNull(toPage);
this.state = Assert.notNull(state);
addClickHandler(this);
addAttachHandler(new Handler() {
@Override
public void onAttachOrDetach(AttachEvent event) {
if (event.isAttached())
initHref(toPage, state);
}