private function addParameters(\DOMElement $parent)
    {
        $data = $this->container->getParameterBag()->all();
        if (!$data) {
            return;
        }

        if ($this->container->isFrozen()) {
            $data = $this->escape($data);
        }

        $parameters = $this->document->createElement('parameters');
        $parent->appendChild($parameters);
        $this->convertParameters($data, 'parameter', $parameters);
    }