code: <E> Observable<E> wrapObservable(Observable<E> obs) {
          return obs.subscribeOn(Schedulers.io()).observeOn(Schedulers.io());
      }
docs: Sets schedulers for API calls observables.
  
  @param obs Observable to set schedulers for.
  @param <E> Class of the service call result.
  @return Observable for API call.