code: @Nullable
    public static String dnsResolve (@Nonnull final String sHostName)
    {
      final InetAddress aAddress = resolveByName (sHostName);
      if (aAddress == null)
        return null;
      return new IPV4Addr (aAddress.getAddress ()).getAsString ();
    }
docs: JavaScript callback function! Do not rename!
  
  @param sHostName
  The host name.
  @return The resolved IP address as String or <code>null</code> if the host
  name could not be resolved.