public virtual void Progressing(TaskAttemptId attemptID)
 {
     //only put for the registered attempts
     //TODO throw an exception if the task isn't registered.
     TaskHeartbeatHandler.ReportTime time = runningAttempts[attemptID];
     if (time != null)
     {
         time.SetLastProgress(clock.GetTime());
     }
 }
 public virtual void Register(TaskAttemptId attemptID)
 {
     runningAttempts[attemptID] = new TaskHeartbeatHandler.ReportTime(clock.GetTime());
 }