public TriggerOption withLateFiringsAtEvery(Duration duration){
  TimeTrigger trigger=new TimeTrigger(Type.LATE,duration);
  triggerList.add(trigger);
  return this;
}

public TriggerOption withLateFiringsAtEvery ( Duration duration ) { TimeTrigger trigger = new TimeTrigger ( Type . LATE , duration ) ; triggerList . add ( trigger ) ; return this ; }
a trigger should be fired after the watermark once for every specified duration
