anchor.diff:        } else {
           var periodic = timer as _PausablePeriodicTimer;
   
  -        periodic.cancel();
  -
           var unpause = continueResumeWithPeriodicAt(scheduled, periodic,
               nextPeriodic: nextPeriodic);
           unpause.startFrom(offset);
  
positive.code:   _PausableNonPeriodicTimer continueResumeWithPeriodicAt(
        _Scheduled scheduled, _PausablePeriodicTimer periodic,
        {Duration nextPeriodic}) {
      var timer = _PausableNonPeriodicTimer.forPeriodic(
          this,
          scheduled.sequence,
  
negative.code:   /// Forked zone with pausable timers
    Zone _zone;
  
    _PausableZone(this._parentOffset, {Zone parent}) {
      parent = parent ?? Zone.current;
      _zone = parent.fork(
          specification: ZoneSpecification(
  