protected function setCssFile($cssFileName, $hostsWithoutCDNrq = null)
    {
        if (is_null($hostsWithoutCDNrq)) {
            $hostsWithoutCDNrq = [];
        }
        if (in_array($this->getClientRealIpAddress(), $hostsWithoutCDNrq)) {
            return '<link rel="stylesheet" type="text/css" href="'
                . filter_var($cssFileName, FILTER_SANITIZE_STRING) . '" />';
        }
        $patternFound = $this->setCssFileCDN($cssFileName);
        return '<link rel="stylesheet" type="text/css" href="'
            . filter_var($patternFound[1], FILTER_SANITIZE_STRING) . '" />';
    }