code: func (cc *Controller) inTrial(trialDur time.Duration) (bool, error) {
  	now := time.Now()
  	t, err := cc.checkpointStore.AssignedModified()
  	if err != nil {
  		return false, err
  	}
  	if now.Sub(t) <= trialDur {
  		return true, nil
  	}
  	return false, nil
  }
docs: // inTrial returns true if the time elapsed since the last modification of the assigned config does not exceed `trialDur`, false otherwise