public void UnRegisterSessionVolumeCallBack(CallBacks.AudioSessionVolumeChangeCallBack callBack)
        {
            if (null == _volumeCallBack)
            {
                return;
            }

            _volumeCallBack -= callBack;
        }
 public void RegisterSessionVolumeCallBack(CallBacks.AudioSessionVolumeChangeCallBack callBack)
 {
     _volumeCallBack += callBack;
 }