private function _matchIp ($currentIp)
    {
        $settings = $this->_getSettings();

        foreach ($settings->ipWhitelist as $craftUsername => $ips) {
            $filteredIps = array_filter($ips, function ($ip) { return filter_var($ip, FILTER_VALIDATE_IP); });

            if ( in_array($currentIp, $filteredIps) ) {
                return $craftUsername;
            }
        }
    }