docs: function selectTab() {
          var href = tab.href.split('#')[1];
          var panel = layout._content.querySelector('#' + href);
          layout._resetTabState(tabs);
          layout._resetPanelState(panels);
          u.addClass(tab, layout._CssClasses.IS_ACTIVE);
          u.addClass(panel, layout._CssClasses.IS_ACTIVE);
      }