ReactiveArchitecture_NowPlayingViewModel_MainPipe.java

uiModelObservable = publishRelayUiEvents
    .observeOn(Schedulers.computation())                
    //Translate UiEvents into Actions
    .compose(transformEventsIntoActions)
    //Asynchronous Actions To Interactor
    .publish(actionObservable -> nowPlayingInteractor.processAction(actionObservable))
    //Scan Results to Update UiModel
    .scan(initialUiModel, (uiModel, result) -> {                   
        if (result instanceof ScrollResult) {
            return processScrollResult(uiModel, (ScrollResult) result);
        } else if (result instanceof ***) {
            return processRestoreResult(uiModel, (***) result);
        }
        throw new IllegalArgumentException("Unknown Result: " + result);
    })
    //Publish results to main thread.
    .observeOn(AndroidSchedulers.mainThread())
    //Save history for late subscribers.
    .replay(1)
    .autoConnect();