How to specify proxy authentication when using RestClient

[Shiva Kumar H R]

The proxy that I am behind requires authentication using an username and
password. I see that using ClientConfig, I can set the proxyHost and
proxyPort, but how do I set the authentication credentials ?

        ClientConfig clientConfig = new ClientConfig();
        clientConfig.proxyHost("myproxy.myorg.in");
        clientConfig.proxyPort(5863);
        //how do I set the proxy username and password?
        RestClient client = new RestClient(clientConfig);
        String url = "http://www.rssboard.org/files/sample-rss-2.xml";;
        Resource resource = client.resource(url);

Thanks,
Shiva Kumar H R