public async Task Deregister()
        {
            var deregisterMsg = new DeregisterMessage();
            deregisterMsg.challengeId = challengeId;
            deregisterMsg.deviceId = deviceId;
            var deregisterMessage = new MessageFrame("deregister", deregisterMsg);

            string message = JsonConvert.SerializeObject(deregisterMessage);

            await connection.SendAsync(message);

            Debug.WriteLine("sent deregister message");
        }
		public async void Deregister (string deviceId, Guid multiplayerChallengeId)
		{
			try {
				var deregisterMsg = new DeregisterMessage (deviceId, multiplayerChallengeId);
				string message = JsonConvert.SerializeObject (deregisterMsg, jsonSerializerSettings);
				await connectionService.Send (message);
				Debug.WriteLine ("sent deregister message");
			} catch (Exception e) {
				Debug.WriteLine ("Deregistering failed: " + e.Message);
			}
		}