static NanoHTTPD.Response serveHTMLNoCache(O html) {
  if (html instanceof NanoHTTPD.Response)
    ret (NanoHTTPD.Response) html;
    
  NanoHTTPD.Response response = serveHTML((S) html);
  response.addHeader("Cache-Control", "no-cache, must-revalidate, max-age=0");
  ret response;
}