SampleObservable.java

        Observable timedObservable = Observable
                .just(1, 2, 3, 4, 5, 6)
                .zipWith(Observable.interval(
                        0, 1, TimeUnit.SECONDS), (item, time) -> item);

        timedObservable
                .sample(2, TimeUnit.SECONDS)
                .subscribe(new Observer() {
                    @Override
                    public void onSubscribe(Disposable d) {

                    }

                    @Override
                    public void onNext(Object o) {
                        System.out.println("onNext: " + o);
                    }

                    @Override
                    public void onError(Throwable e) {

                    }

                    @Override
                    public void onComplete() {

                    }
                });