public function seoFriendlyUrl(string $str): string
    {
        /* Make alphanumeric and lowercase (removes all other characters) */
        $str = preg_replace('/[^a-z0-9_\s-]/', '', strtolower($str));

        /* Clean up multiple dashes or whitespaces */
        $str = preg_replace('/[\s-]+/', ' ', $str);

        /* Convert whitespaces and underscore to dash */
        $str = preg_replace('/[\s_]/', '-', $str);

        return $str;
    }