Site site = navigation.getSite();
String navUri = operationContext.getAddress().resolvePathTemplate("nav-uri");
SiteKey siteKey = getSiteKey(site);
DescriptionService descriptionService = operationContext.getRuntimeContext().getRuntimeComponent(DescriptionService.class);
NavigationService navigationService = operationContext.getRuntimeContext().getRuntimeComponent(NavigationService.class);
BindingProvider bindingProvider = operationContext.getBindingProvider();
Marshaller<PageNavigation> marshaller = bindingProvider.getMarshaller(PageNavigation.class, ContentType.XML);
NavigationExportTask exportTask = new NavigationExportTask(new NavigationKey(siteKey, navUri), navigationService, descriptionService, marshaller);