t>
test(function () {
  // See https://dom.spec.whatwg.org/#stop-propagation-flag
  var e = document.createEvent('Event');
  assert_false(e.cancelBubble, "cancelBubble must be false after event creation.");
}, "cancelBubble must be false when an event is initially created.");

test(function () {
  // See https://dom.spec.whatwg.org/#concept-event-initialize

  // Event which bubbles.
  var one = document.createEvent('Event');
  one.cancelBubble = true;
  one.initEvent('foo', true/*bubbles*/, false/*cancelab