code: function privateBrowsing_stop(useShortcut)
    {
      if (!this.enabled)
        return;
  
      if (useShortcut) {
        var privateBrowsingCmdKey = utils.getEntity(this.getDtds(), "privateBrowsingCmd.commandkey");
        this._controller.keypress(null, privateBrowsingCmdKey, {accelKey: true, shiftKey: true});
      } else {
        this._controller.click(this._pbMenuItem);
      }
  
      this.waitForTransistionComplete(false);
    }
docs: Stop the Private Browsing mode
  
  @param {boolean} useShortcut
  Use the keyboard shortcut if true otherwise the menu entry is used