code: private GridHubConfiguration getHubConfiguration() throws Exception {
      String hubApi =
          "http://" + registrationRequest.getConfiguration().getHubHost() + ":"
          + registrationRequest.getConfiguration().getHubPort() + "/grid/api/hub";
  
      URL api = new URL(hubApi);
      HttpClient client = httpClientFactory.createClient(api);
      String url = api.toExternalForm();
      HttpRequest request = new HttpRequest(GET, url);
  
      HttpResponse response = client.execute(request);
      try (Reader reader = new StringReader(response.getContentString());
           JsonInput jsonInput = new Json().newInput(reader)) {
        return GridHubConfiguration.loadFromJSON(jsonInput);
      }
    }
docs: uses the hub API to get some of its configuration.
  
  @return json object of the current hub configuration