public function isIpWhitelisted($ipAddress)
    {
        // determine whether this IP is IPv4 or IPv6
        $isIpv4Address = filter_var($ipAddress, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4);
        return $this->isIpInWhitelist(
            ($isIpv4Address) ? $this->ipv4Whitelist : $this->ipv6Whitelist,
            $ipAddress
        );
    }