public async Task LogOut()
        {
            if (selfId == string.Empty)
            {
                //throw new BusinessException("logout before login?");
                Logger.LogWarning("logout before login ?");
            }

            try
            {
                await grpcClient.LogoutAsync(new LogoutRequest());
            }
            catch (Exception ex)
            {
                Logger.LogError($"loginout() exception :{ex.StackTrace}");
            }
        }