RxAppStateMonitor { @NonNull public static Observable<AppState> monitor(@NonNull Application app) { return monitor(app, NONE); }  @NonNull static Observable<AppState> monitor(@NonNull Application app); @NonNull static Observable<AppState> monitor(@NonNull Application app, @NonNull
        Emitter.BackpressureMode backpressureMode);  }
@Test public void emitsAppStates() { FakeApplication fakeApplication = new FakeApplication(); TestSubscriber<AppState> subscriber = TestSubscriber.create(); RxAppStateMonitor.monitor(fakeApplication).subscribe(subscriber); fakeApplication.goForeground(); fakeApplication.goBackground(); subscriber.assertValues(FOREGROUND, BACKGROUND); subscriber.assertNoTerminalEvent(); }