How to use google play review reply api on java?

I wanna use this API of google but couldn't find any code examples for java. Can anybody help with giving code examples? (i am already listing reviews, I just need to know how to use API to reply reviews.)

https://developers.google.com/android-publisher/reply-to-reviews

My review listing code:

public List<Review> getReviews(String package_name) {

        GoogleCredentials credential = null;
        try {
            credential = GoogleCredentials.fromStream(new FileInputStream("service.json"))
                    .createScoped(Collections.singleton(AndroidPublisherScopes.ANDROIDPUBLISHER));
            HttpTransport httpTransport = new NetHttpTransport();
            JsonFactory jsonFactory = new GsonFactory();

            HttpRequestInitializer requestInitializer = new HttpCredentialsAdapter(credential);
            AndroidPublisher publisher = new AndroidPublisher(httpTransport, jsonFactory, requestInitializer);
            //publisher.reviews().reply()



            ReviewsListResponse reviews = publisher.reviews().list(package_name).execute();



            return reviews.getReviews();

        } catch (IOException e) {
            e.printStackTrace();
        }

        return null;
    }