public function clean($delimiter = '-')
    {
        // The fileextension should not be normalized.
        if (strrpos($this->filename, '.') !== false) {
            list ($name, $extension) = explode('.', $this->filename);
        }

        $normalize = new Normalize($name);

        $name = $normalize->normalize();
        $name = preg_replace('/[^[:alnum:]\-]+/', $delimiter, $name);
        $name = preg_replace('/' . $delimiter . '+/', $delimiter, $name);
        $name = rtrim($name, $delimiter);

        $cleaned = isset($extension) ? $name . '.' . $extension : $name;

        return $cleaned;
    }