/** * This method indicating downloading file status if model download from passio server. * @param callback - A callback to receive for dowloading file lefts from queue. * @param callback - A callback to receive dowload file failed for some reason. * @returns A `Callback` that should be retained by the caller while dowloading is running. Call `remove` on the callback to terminate listeners and relase from memory. */ onDowloadingPassioModelCallBacks: ( downloadModelCallBack: DownloadModelCallBack ) => Callback