static L youTubeGetChatMessages(S liveStreamID) {
  S url ="https://www.googleapis.com/youtube/v3/liveChat/messages?liveChatId=" + urlencode(liveStreamID) + "&part=id,snippet,authorDetails&key=" + youTubeDataAPIKey();
  Map map = cast loadJSONPage(url);
  printStruct(map);
  L<Map> items = cast map.get('items);
  ret map(items, func(Map item) -> S {
    Map snippet = cast item.get('snippet);
    Map textMessageDetails = cast _get(snippet, 'textMessageDetails);
    ret getString(textMessageDetails, 'messageText);
  });
}