protected function _load($key)
    {
        $parts = explode('.', $key);
        $first = array_shift($parts);
        if (isset($this->_loaded[$first])) {
            return;
        }
        $cookie = $this->getController()->getRequest()->getCookie($first);
        if ($cookie === null) {
            return;
        }
        $config = $this->configKey($first);
        $this->_loaded[$first] = true;
        $this->_values[$first] = $this->_decrypt($cookie, $config['encryption'], $config['key']);
    }