public async Task <IPlatformResponse <TTr> > AddObserverTransport <TTr>(ObserverEntity entity, string observerKey, ITransport transport, CancellationToken?cancellationToken = null, IProgress <ISDKProgress> progress = null) where TTr : ITransport { SetupTokenAndProgress(cancellationToken, progress); return(await SdkClient.AddObserverTransport <TTr>(entity, observerKey, transport, cancellationToken, progress)); }