public async Task<IHttpActionResult> SendNotificationAsync([FromBody] string message)
        {
            HttpConfiguration config = this.Configuration;
            try
            {
                await SendNotification(message, null);
            }
            catch(Exception ex)
            {
                config.Services.GetTraceWriter().Error(
                  ex.Message , null, "Push.SendAsync Error");
                return BadRequest(ex.Message);
            }
        }