What about offline first, live local datastore updates

Hi all.

Alright in my project I followed an offline first architecture where I'm always Querying the local datastore. For each ressources that requires query, a `Presenter` has two `UseCase`objects:
1. One that makes requests to the remote data store and save it locally, it never deliver information to presenter, the `rx.Subscriber` only does Logging. All saving operations are performed in `doOnNext`.
2. Another one that is directly subscribed to the local dataStore and listen for insertion/deletion/updates via an Observable so that once something is changed it queries data and present it to the view.

``` Java
final FetchArticleCollectionUseCase mFetchArticleCollectionUseCase;
final GetArticleUpdatesUseCase mGetArticleUpdatesUseCase;
```

It's working pretty well now. But I'm wondering if I'm still making a good use of `UseCase`. And I personally find it cumbersome to write two `UseCase` for one data output every time.