code: @Override
      public synchronized ServerBootstrap newServerBootstrap() throws Exception {
          if (serverChannelFactory == null) {
              Executor workerExecutor = executorServiceFactory.newExecutorService("worker.server");
              NioDatagramWorkerPool workerPool = new NioDatagramWorkerPool(workerExecutor, 1);
              serverChannelFactory = new UdpServerChannelFactory(workerPool, timer);
  
              // unshared
              channelFactories.add(serverChannelFactory);
          }
  
          return new ServerBootstrap(serverChannelFactory);
      }
docs: Returns a {@link ServerBootstrap} instance for the named transport.