/// <summary> /// Register/Unregister a Google Cloud Messaging registration ID. /// </summary> /// <param name="token">The cancellation token</param> /// <param name="gcmRegistrationId">The GCM id to register. A call with an absent value will unregister.</param> /// <returns></returns> public async Task SetGcmId(CancellationToken token, string gcmRegistrationId)// throws IOException { if (gcmRegistrationId != null) { await PushServiceSocket.RegisterGcmId(token, gcmRegistrationId); } else { await PushServiceSocket.UnregisterGcmId(token); } }