it('should process micro-tasks created in timers before next timers', fakeAsync(() => {
           var log = new Log();

           PromiseWrapper.resolve(null).then((_) => log.add('microtask'));

           TimerWrapper.setTimeout(() => {
             log.add('timer');
             PromiseWrapper.resolve(null).then((_) => log.add('t microtask'));
           }, 9);

           var id = TimerWrapper.setInterval(() => {
             log.add('periodic timer');
             PromiseWrapper.resolve(null).then((_) => log.add('pt microtask'));
           }, 10);

           tick(10);
           expect(log.result())
               .toEqual('microtask; timer; t microtask; periodic timer; pt microtask');

           tick(10);
           expect(log.result())
               .toEqual(
                   'microtask; timer; t microtask; periodic timer; pt microtask; periodic timer; pt microtask');

           TimerWrapper.clearInterval(id);
         }));

 beforeEach(() => {
   log = new Log();
   zone = new VmTurnZone({enableLongStackTrace: true});
   zone.initCallbacks({
     onTurnStart: log.fn('onTurnStart'),
     onTurnDone: log.fn('onTurnDone')
   });
 });

 PromiseWrapper.resolve(null).then((_) => log.add(2));