@Override
  protected void execute(OperationContext operationContext, ResultHandler resultHandler, Site site)
      throws ResourceNotFoundException, OperationException {
    Navigation navigation = site.getRootNavigation().getChild("default");
    if (navigation == null)
      throw new ResourceNotFoundException("Navigation does not exist for site " + getSiteKey(site));

    execute(operationContext, resultHandler, navigation);
  }
  private Page getPagesFrom(Site site) {
    // a site contains a root page with templates and pages
    // more info at http://code.google.com/p/chromattic/wiki/MOPUseCases

    return site.getRootPage().getChild(PAGES_CHILD_NAME);
  }