class Contracts {

    public static String resolveRegistryContract(String chainId) {
        switch (Byte.valueOf(chainId)) {
            case ChainId.MAINNET:
                return MAINNET;
            case ChainId.ROPSTEN:
                return ROPSTEN;
            case ChainId.RINKEBY:
                return RINKEBY;
            default:
                throw new EnsResolutionException(
                        "Unable to resolve ENS registry contract for network id: " + chainId);
        }
    }

}