docs: function updateSelectedPages() {
          var node = util.getSelectedNode();
          var $page = $(node).closest('.'+CSS_CLASS_PAGE);
          $el.find('.'+CSS_CLASS_TEXT_SELECTED).removeClass(CSS_CLASS_TEXT_SELECTED);
          if (node && $el.has(node)) {
              $page.addClass(CSS_CLASS_TEXT_SELECTED);
          }
      }