ReplaySubjectExample.java

        ReplaySubject<Integer> pSubject = ReplaySubject.create();
        pSubject.onNext(0);


        pSubject.subscribe(it -> System.out.println("Observer 1 onNext: " + it),
                (Throwable error) -> { }, () -> {},
                on1 -> System.out.println("Observer 1 onSubscribe"));

        pSubject.onNext(1);
        pSubject.onNext(2);


        pSubject.subscribe(it -> System.out.println("Observer 2 onNext: " + it),
                (Throwable error) -> { }, () -> {},
                on1 -> System.out.println("Observer 2 onSubscribe"));

        pSubject.onNext(3);
        pSubject.onNext(4);