public async Task <IPlatformResponse <IPushObserverResponse> > ObserveUser(Guid userId, IPushObserver observer, CancellationToken?cancellationToken = null, IProgress <ISDKProgress> progress = null)
{
SetupTokenAndProgress(cancellationToken, progress);
return(await SdkClient.ObserveUser(userId, observer, cancellationToken, progress));
}