Chaining-rxjava-2.java

// DiskRepository.java
@RxLogObservable
public Observable<Data> getData() {
    // implementation
}

// NetworkRepository.java
@RxLogObservable
public Observable<Data> getData() {
    // implementation
}

// DomainService.java
@RxLogObservable
public Observable<Data> getMergedData() {
  return Observable.merge(
    diskRepository.getData().subscribeOn(Schedulers.io()),
    networkRepository.getData().subscribeOn(Schedulers.io())
  );
}