protected function getClonedNodes()
    {
        $cloned_nodes = array();

        foreach ($this->nodes as $node) {
            $cloned_node = $node->cloneNode(true);

            if ($cloned_node instanceof \DOMElement && $cloned_node->hasAttribute('dqn_tmp_id')) {
                $cloned_node->removeAttribute('dqn_tmp_id');
            }

            $cloned_nodes[] = $cloned_node;
        }

        return $cloned_nodes;
    }