code: public Observable<List<TopicTypeInfoInner>> listAsync() {
          return listWithServiceResponseAsync().map(new Func1<ServiceResponse<List<TopicTypeInfoInner>>, List<TopicTypeInfoInner>>() {
              @Override
              public List<TopicTypeInfoInner> call(ServiceResponse<List<TopicTypeInfoInner>> response) {
                  return response.body();
              }
          });
      }
docs: List topic types.
  List all registered topic types.
  
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the List&lt;TopicTypeInfoInner&gt; object