code: public synchronized void start() throws IOException {
      if (responder.isAlive()) {
        // The server is already running
        return;
      }
      responder.start();
      listener.start();
      handlers = new Handler[handlerCount];
  
      for (int i = 0; i < handlerCount; i++) {
        handlers[i] = new Handler(i);
        handlers[i].start();
      }
    }
docs: Starts the service.  Must be called before any calls will be handled.