docs: public static void main(String[] args) throws Exception {
      if (args.length < 2) {
        logger.severe("Usage: please pass 2 arguments:\n" +
                      "arg0 = location of the JSON file for the service account you created in the GCP console\n" +
                      "arg1 = project name in the form \"projects/xyz\" where \"xyz\" is the project ID of the project you created.\n");
        System.exit(1);
      }
      GoogleCredentials credentials = GoogleCredentials.fromStream(new FileInputStream(args[0]));
  
      // We need to create appropriate scope as per https://cloud.google.com/storage/docs/authentication#oauth-scopes
      credentials = credentials.createScoped(Arrays.asList("https://www.googleapis.com/auth/cloud-platform"));
  
      // credentials must be refreshed before the access token is available
      credentials.refreshAccessToken();
      GoogleAuthClient client =
              new GoogleAuthClient("pubsub.googleapis.com", 443, MoreCallCredentials.from(credentials));
  
      try {
        client.getTopics(args[1]);
      } finally {
        client.shutdown();
      }
    }