public function clear(Config $means, Config $target)
    {
        foreach ($target as $key => $value) {
            if ($value instanceof BaseConfig && isset($means[$key])) {
                $this->clear($means[$key], $value);
            } else {
                if (isset($means[$key])) {
                    $target->offsetUnset($key);
                }
            }
        }

        return new BaseConfig($target->toArray());
    }