protected function transformAttrToAssoc($node_map)
    {
        // NamedNodeMap is documented very well, so we're using undocumented
        // features, namely, the fact that it implements Iterator and
        // has a ->length attribute
        if ($node_map->length === 0) {
            return array();
        }
        $array = array();
        foreach ($node_map as $attr) {
            $array[$attr->name] = $attr->value;
        }
        return $array;
    }