docs: @Handler
      public void onStart(Start event) throws IOException {
          closing = false;
          serverSocketChannel = ServerSocketChannel.open();
          serverSocketChannel.bind(serverAddress, backlog);
          MBeanView.addServer(this);
          fire(new NioRegistration(this, serverSocketChannel,
              SelectionKey.OP_ACCEPT, this), Channel.BROADCAST);
      }