text: kuzzleio::NotificationListener listener =
    [](const std::shared_ptr<kuzzleio::notification_result> &notification){};
  
  try {
    std::string room_id = kuzzle->realtime->subscribe(
      "nyc-open-data",
      "yellow-taxi",
      "{}",
      &listener);
  
    int count = kuzzle->realtime->count(room_id);
  
    std::cout << "Currently " << count << " active subscription" << std::endl;
  } catch (kuzzleio::KuzzleException &e) {
    std::cerr << e.what() << std::endl;
  }
  