class HappyEyeballsResolver implements SocketAddressResolver {

    Optional<String> isLiteralIpAddress(String host) {
        if (isLiteralV4Address(host)) return Optional.of(host);
        else if (host.contains(":")) {
            final Matcher matcher = IPV6_ADDRESS_PATTERN.matcher(host);
            if (matcher.matches()) return Optional.of(matcher.group(1));
        }
        return Optional.empty();
    }

    public  HappyEyeballsResolver(HttpClient httpClient);

}