docs: function () {
              if (!this.storage) {
                  return;
              }
              var listeners = !!this._listeners;
              var registeredBrowserEvent = !!this._browserEventCb;
  
              if (listeners !== registeredBrowserEvent) {
                  if (listeners) {
                      this._browserEventCb = {
                          fn : this._browserEvent,
                          scope : this
                      };
                      // listen to events raised by instances in a different window but the same storage location
                      ariaUtilsEvent.addListener(Aria.$window, "storage", this._browserEventCb);
                  } else {
                      ariaUtilsEvent.removeListener(Aria.$window, "storage", this._browserEventCb);
                      this._browserEventCb = null;
                  }
              }
  
          }