code: @Test public void testConnectionClose() throws Exception {
    DefaultServer.setRootHandler(SIMPLE_MESSAGE_HANDLER);
    final UndertowClient client=createClient();
    final CountDownLatch latch=new CountDownLatch(1);
    final ClientConnection connection=client.connect(ADDRESS,worker,new ByteBufferSlicePool(1024,1024),OptionMap.EMPTY).get();
    try {
      ClientRequest request=new ClientRequest().setPath("/1324").setMethod(Methods.GET);
      final List<ClientResponse> responses=new CopyOnWriteArrayList<ClientResponse>();
      request.getRequestHeaders().add(Headers.CONNECTION,Headers.CLOSE.toString());
      connection.sendRequest(request,createClientCallback(responses,latch));
      latch.await();
      final ClientResponse response=responses.iterator().next();
      Assert.assertEquals(message,response.getAttachment(RESPONSE_BODY));
      try {
        request=new ClientRequest().setPath("/1324").setMethod(Methods.GET);
        connection.sendRequest(request,createClientCallback(responses,latch));
        Assert.fail();
      }
   catch (    IllegalStateException e) {
      }
    }
    finally {
      IoUtils.safeClose(connection);
    }
  }
  