static async Task SubjectAsync() { var subject = new SequentialSimpleAsyncSubject <int>(); var res = subject.Where(x => x % 2 == 0).Select(x => x + 1); await res.SubscribeAsync(Print <int>()); for (var i = 0; i < 10; i++) { await subject.OnNextAsync(i); } await subject.OnCompletedAsync(); }