private async Task <ISet <PubSubSubscriptionState> > RegisterProducer()
{
var tup = await providerRuntime.BindExtension <SimpleMessageStreamProducerExtension, IStreamProducerExtension>(
() => new SimpleMessageStreamProducerExtension(providerRuntime, fireAndForgetDelivery));
myExtension = tup.Item1;
myGrainReference = tup.Item2;
myExtension.AddStream(stream.StreamId);
// Notify streamRendezvous about new stream streamProducer. Retreave the list of RemoteSubscribers.
return(await pubSub.RegisterProducer(stream.StreamId, streamProviderName, myGrainReference));
}