docs: public Observable<Page<ProviderInner>> listAsync() {
          return listWithServiceResponseAsync()
              .map(new Func1<ServiceResponse<Page<ProviderInner>>, Page<ProviderInner>>() {
                  @Override
                  public Page<ProviderInner> call(ServiceResponse<Page<ProviderInner>> response) {
                      return response.body();
                  }
              });
      }