SubscriptionHandled.cs

IDisposable? subscription = null;
        subscription = session.On(evt =>
        {
            switch (evt)
            {
                case AssistantMessageDeltaEvent delta
                    when !string.IsNullOrEmpty(delta.Data?.DeltaContent):
                    channel.Writer.TryWrite(delta.Data.DeltaContent);
                    break;

                case SessionIdleEvent:
                    channel.Writer.TryComplete();
                    subscription?.Dispose();
                    break;
            }
        });