var subject = new Subject<int>();

//IDispose를 저장
var disposable = subject.Subscribe(x => Debug.Log(x), () => Debug.Log("OnCompleted"));  //Subscribe(OnNext, OnCompleted) 오버로드

subject.OnNext(1);
subject.OnNext(2);
//Subscribe 종료
disposable.Dispose();
//-----이 아래는 Subscribe  않음-----//
subject.OnNext(3);
subject.OnCompleted();

//---결과---//
1
2