public function clear(array $excepts = [])
    {
        $tmp = array();
        foreach ($excepts as $except) {
            if ($this->has($except)) {
                $tmp[$except] = $this->get($except);
            }
        }
        $this->setAll(array());
        foreach ($tmp as $key => $value) {
            $this->set($key, $value);
        }
    }