code: public Observable<List<FluentModelTImpl>> commitAndGetAllAsync() {
          return commitAsync().collect(
                  new Func0<List<FluentModelTImpl>>() {
                      public List<FluentModelTImpl> call() {
                          return new ArrayList<>();
                      }
                  },
                  new Action2<List<FluentModelTImpl>, FluentModelTImpl>() {
                      public void call(List<FluentModelTImpl> state, FluentModelTImpl item) {
                          state.add(item);
                      }
                  });
      }
docs: Commits the changes in the external child resource childCollection.
  <p/>
  This method returns a observable stream, either its observer's onError will be called with
  {@link CompositeException} if some resources failed to commit or onNext will be called if all resources
  committed successfully.
  
  @return the observable stream