public static HttpRequest newUpgradeRequest(String ext) {
HttpRequest req = ReferenceCountUtil.releaseLater(new DefaultHttpRequest(
HttpVersion.HTTP_1_1, HttpMethod.GET, "/chat"));
req.headers().set(HttpHeaderNames.HOST, "server.example.com");
req.headers().set(HttpHeaderNames.UPGRADE, HttpHeaderValues.WEBSOCKET);
req.headers().set(HttpHeaderNames.CONNECTION, "Upgrade");
req.headers().set(HttpHeaderNames.ORIGIN, "http://example.com");
if (ext != null) {
req.headers().set(HttpHeaderNames.SEC_WEBSOCKET_EXTENSIONS, ext);