code: func afterOrZero(t1, t2 *metav1.Time) bool {
  	if t1.Time.IsZero() || t2.Time.IsZero() {
  		return t1.Time.IsZero()
  	}
  	return t1.After(t2.Time)
  }
docs: // afterOrZero checks if time t1 is after time t2; if one of them
  // is zero, the zero time is seen as after non-zero time.