public function renderContentNode(array $contentNode, array $params = array()) {
        if (empty($contentNode)) {
            return '';
        }
        $model = strtolower($contentNode['model']);
        $type  = $contentNode['type'] ?: 'default';
        $partial = "partials/chapters/$model/$type.phtml";
        $params['contentNode'] = $contentNode;
        return $this->view->partial($partial, 'default', $params);
    }