ntrTests := []struct {
		input string
		err   error
	}{
		{
			input: `<NoncurrentVersionTransition>
			<NoncurrentDays>0</NoncurrentDays>
			<StorageClass>S3TIER-1</StorageClass>
		  </NoncurrentVersionTransition>`,
			err: nil,
		},
		{
			input: `<NoncurrentVersionTransition>
			<Days>1</Days>
		  </NoncurrentVersionTransition>`,
			err: errXMLNotWellFormed,
		},
	}

	for i, tc := range ntrTests {

	}
	return nil
}

// NoncurrentVersionTransition - an action for lifecycle configuration rule.
type NoncurrentVersionTransition struct {
	NoncurrentDays TransitionDays `xml:"NoncurrentDays"`
	StorageClass   string         `xml:"StorageClass"`
	set            bool
}

// MarshalXML is extended to leave out
// <NoncurrentVersionTransition></NoncurrentVersionTransition> tags

	NoncurrentVersionExpiration NoncurrentVersionExpiration `xml:"NoncurrentVersionExpiration,omitempty"`
	NoncurrentVersionTransition NoncurrentVersionTransition `xml:"NoncurrentVersionTransition,omitempty"`
}

var (
	errInvalidRuleID                  = Errorf("ID length is limited to 255 characters")
	errEmptyRuleStatus                = Errorf("Status should not be empty")

	}
	tags[ilmAction] = event.Action.String()
	tags[ilmRuleID] = event.RuleID

	if !event.Due.IsZero() {
		tags[ilmDue] = event.Due.Format(iso8601Format)
	}

	// rule with Transition/NoncurrentVersionTransition in effect
	if event.StorageClass != "" {
		tags[ilmTier] = event.StorageClass
	}

	// rule with NewernoncurrentVersions in effect
	if event.NewerNoncurrentVersions > 0 {