docs: public Observable<List<Person>> listAsync(String personGroupId, ListPersonGroupPersonsOptionalParameter listOptionalParameter) {
          return listWithServiceResponseAsync(personGroupId, listOptionalParameter).map(new Func1<ServiceResponse<List<Person>>, List<Person>>() {
              @Override
              public List<Person> call(ServiceResponse<List<Person>> response) {
                  return response.body();
              }
          });
      }