docs: private void sendClosingSignal() {
          URL clientURL = null;
          HttpsURLConnection connection = null;
          try {
              // Get the appropriate URL to delete notification client
              if (serverConnection.serverVersion >= 4) {
                  //V4+ clients use /{clientID} to delete the notification client
                  clientURL = getNotificationClientURL();
              } else {
                  //Pre-V4 clients use /{clientID}/inbox to delete the notification client
                  clientURL = getInboxURL();
              }
  
              if (logger.isLoggable(Level.FINEST)) {
                  logger.logp(Level.FINEST,
                              logger.getName(),
                              "sendClosingSignal",
                              "Making a call to delete inbox [" + clientURL + "] from ["
                                              + RESTClientMessagesUtil.getObjID(this) + "]");
              }
              // Get connection to server
              connection = serverConnection.getConnection(clientURL, HttpMethod.DELETE, true);
              connection.setReadTimeout(serverConnection.getConnector().getReadTimeout());
  
              // Check response code from server
              int responseCode = 0;
              try {
                  responseCode = connection.getResponseCode();
              } catch (ConnectException ce) {
                  logger.logp(Level.FINE, logger.getName(), "sendClosingSignal", ce.getMessage(), ce);
              }
  
              if (logger.isLoggable(Level.FINEST)) {
                  logger.logp(Level.FINEST, logger.getName(), "sendClosingSignal", "Response code: " + responseCode);
              }
  
          } catch (IOException io) {
              logger.logp(Level.FINE, logger.getName(), "sendClosingSignal", io.getMessage(), io);
          }
      }