docs: public static <InnerT> Observable<InnerT> convertListToInnerAsync(Observable<List<InnerT>> innerList) {
          return innerList.flatMap(new Func1<List<InnerT>, Observable<InnerT>>() {
              @Override
              public Observable<InnerT> call(List<InnerT> inners) {
                  return Observable.from(inners);
              }
          });
      }