code: public static void setDefaultProxy(String hostName,int port,String user)
                               throws UnknownHostException{
        defaultProxy = new Socks4Proxy(hostName,port,user);
     }
docs: Sets SOCKS4 proxy as default.
  @param hostName Host name on which SOCKS4 server is running.
  @param port Port on which SOCKS4 server is running.
  @param user Username to use for communications with proxy.