The Tor Browser / file revision

 /* Any copyright is dedicated to the Public Domain.

  * http://creativecommons.org/publicdomain/zero/1.0/ */

 const Cc = Components.classes;

 const Ci = Components.interfaces;

 const DELAY_MS = "2000";

 let timer;

 function handleRequest(req, resp) {

   resp.processAsync();

   resp.setHeader("Cache-Control", "no-cache", false);

   resp.setHeader("Content-Type", "text/html;charset=utf-8", false);

   timer = Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer);

   timer.init(() => {

     resp.write("hi");

     resp.finish();

   }, DELAY_MS, Ci.nsITimer.TYPE_ONE_SHOT);

 }