if (!e.IsDaysNull() || !e.IsDateNull()) && e.DeleteMarker.set {
		return errLifecycleInvalidDeleteMarker
	}

	if !e.DeleteMarker.set && !e.DeleteAll.set && e.IsDaysNull() && e.IsDateNull() {
		return errXMLNotWellFormed
	}

	// Both expiration days and date are specified
	if !e.IsDaysNull() && !e.IsDateNull() {
		return errLifecycleInvalidExpiration
	}

func (t Transition) Validate() error {
	if !t.set {
		return nil
	}

	if !t.IsDateNull() && t.Days > 0 {
		return errTransitionInvalid
	}

	if t.StorageClass == "" {
		return errXMLNotWellFormed
	}
	return nil
}

// IsDateNull returns true if date field is null
func (t Transition) IsDateNull() bool {
	return t.Date.Time.IsZero()
}

		if !rule.NoncurrentVersionTransition.IsNull() {
			return true
		}
		if !rule.Expiration.IsDateNull() && rule.Expiration.Date.Before(time.Now().UTC()) {
			return true
		}
		if !rule.Expiration.IsDaysNull() {
			return true
		}
		if rule.Expiration.DeleteMarker.val {
			return true
		}
		if !rule.Transition.IsDateNull() && rule.Transition.Date.Before(time.Now().UTC()) {
			return true
		}