code: public void setSocksProxy(String host) {
      assertNotMobile();
      setProxyValue(SOCKS_SERVER, host);
      setProxyValue(USE_SOCKS, host != null);
    }
docs: Specifies which proxy to use for SOCKS.  Currently only supported in {@link
  com.opera.core.systems.OperaDriver}.
  
  @param host the proxy host, expected format is <code>hostname.com:1234</code>