static void web_addLabelsFromNodeToNode(WebNode src, WebNode dest) {
  if (src == dest) ret;
  web_addLabels(dest, src.labels);
}

static void web_addLabelsFromNodeToNode(Map<WebNode> map) {
  for (WebNode key, value : map) {
    web_addLabelsFromNodeToNode(key, value);
  }
}