protected void execute(OperationContext operationContext, ResultHandler resultHandler, Navigation defaultNavigation) {
SiteKey siteKey = getSiteKey(defaultNavigation.getSite());
String navUri = operationContext.getAddress().resolvePathTemplate("nav-uri");
NavigationService navigationService = operationContext.getRuntimeContext().getRuntimeComponent(NavigationService.class);
NavigationContext navigation = navigationService.loadNavigation(siteKey);
Set<String> children = new LinkedHashSet<String>();
NodeContext<NodeContext<?>> node = NavigationUtils.loadNode(navigationService, navigation, navUri);
if (node == null) {