code: function __bindController (newController, sessionExpiration) {
      if (controller && typeof(controller.shutdown) === 'function') {
          controller.shutdown();
      }
      controller = newController;
      if (typeof(controller.clientInit) === 'function') {
          controller.clientInit(sessionExpiration);
      }
  }
docs: Establish a new session whether first time or because of expiry / server restart