Websocket is null in case of Socks proxy

Hi, I implemented this part of code to connect to a Websocket via SOCKS proxy but the websocket returned is always null. Is it supported?

ProxyServer.Builder socksProxy = Dsl.proxyServer(socksAddress);
socksProxy.setProxyType(ProxyType.SOCKS_V5);

        Builder config = Dsl.config();
        DefaultAsyncHttpClientConfig.Builder as = config.setProxyServer(socksProxy.build());
        AsyncHttpClient ahClient = Dsl.asyncHttpClient(as);

        WebSocketUpgradeHandler.Builder wsbuilder = new WebSocketUpgradeHandler.Builder();

        WebSocketListener mywebSocketListener = new MyWebSocketListener();
        try {
            WebSocketUpgradeHandler handler = wsbuilder.addWebSocketListener(mywebSocketListener).build();

            websocket = ahClient.prepareGet(SODConfiguration.getInstance().getWSUrl()).execute(handler).get(1, TimeUnit.SECONDS);

           
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }