public static function css($fileName, $base_path = true)
    {
        if (!is_array($fileName))
            $fileName = array($fileName);
        $data = null;
        foreach ($fileName as $file)
        {
            $url = "";
            $url .= ($base_path) ? self::getCSSLink() : '';
            $url .= $file;
            $data .= '<link rel="stylesheet" type="text/css" href="' . $url . '"/>' . PHP_EOL;
        }
        
        return $data;
    }