code: function (ev) {
              var self = this;
              self.callSuper(ev);    // combobox menu tap penetration
                                     // https://github.com/kissyteam/kissy/issues/533
              // combobox menu tap penetration
              // https://github.com/kissyteam/kissy/issues/533
              ev.preventDefault();
              self.fire('click');
              return true;
          }
docs: do not set highlighted on mousedown for touch device! only set active in component/control 
  Perform default action when click on enter on this menuitem.
  @protected