public static function fileName($string, $ext = 'php', $capitalize = true) {
        if (mb_strpos($string, '.') !== false) {
            $string = mb_substr($string, 0, mb_strrpos($string, '.'));
        }

        $path = static::camelCase($string);

        if (!$capitalize) {
            $path = lcfirst($path);
        }

        if (mb_substr($path, -(mb_strlen($ext) + 1)) !== '.' . $ext) {
            $path .= '.' . $ext;
        }

        return $path;
    }