Test1.java

public class ApplicationTest extends ApplicationTestCase<Application> {
    private static final String TAG = "Test";

    public ApplicationTest() {
        super(Application.class);
    }

    public void testRxSample() throws InterruptedException {
        final CountDownLatch signal = new CountDownLatch(1);
        final String[] last = new String[1];

        Observable.just("one", "two", "three", "four", "five")
                .subscribeOn(Schedulers.newThread())
                .observeOn(AndroidSchedulers.mainThread())
                .subscribe(new Subscriber<String>() {
                    @Override
                    public void onCompleted() {
                        Log.d(TAG, "completed");
                        signal.countDown();
                    }

                    @Override
                    public void onError(Throwable e) {

                    }

                    @Override
                    public void onNext(String s) {
                        Log.d(TAG, "onNext: " + s);
                        last[0] = s;
                    }
                })
        ;

        signal.await(5, TimeUnit.SECONDS);
        assertEquals("five", last[0]);
    }
}