Repository Design Pattern in Android using RxJava, Retrofit, SQLBrite and SQLDelight

BaseRepository.java

public interface BaseRepository<T> {
    Observable<T> add(T item);
    Observable<List<T>> add(List<T> items);
    Observable<T> query(long id);
    Observable<List<T>> query();
    Observable<T> update(T item);
    Observable<Integer> remove(T item);
}