public function getAddressInfo($ipAddress)
    {
        // This test is a trick to determine if we have a valid IPv4 address, the
        // only kind we can handle at the moment.
        $long = ip2long($ipAddress);
        if ($long == -1 || $long === false) {
            return null;
        }
        $result = $this->gateway->get(
            'ipv4address',
            ['ip_address' => $ipAddress, '_max_results' => 1]
        );
        return (isset($result[0])) ? $result[0] : null;
    }