private function FlagsString()
    {
        $result = '';
        foreach ($this->flags as $flag)
        {
            if ($result)
            {
                $result .= ',';
            }
            $result .= $flag->ToString();
        }
        if ($result)
        {
            $result = '[' . $result . ']';
        }
        return $result;
    }