code: public Observable<Page<FeatureResultInner>> list1Async(final String resourceProviderNamespace) {
          return list1WithServiceResponseAsync(resourceProviderNamespace)
              .map(new Func1<ServiceResponse<Page<FeatureResultInner>>, Page<FeatureResultInner>>() {
                  @Override
                  public Page<FeatureResultInner> call(ServiceResponse<Page<FeatureResultInner>> response) {
                      return response.body();
                  }
              });
      }
docs: Gets all the preview features in a provider namespace that are available through AFEC for the subscription.
  
  @param resourceProviderNamespace The namespace of the resource provider for getting features.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the PagedList&lt;FeatureResultInner&gt; object