func (t *Transition) UnmarshalXML(d *xml.Decoder, startElement xml.StartElement) error {
	type transitionWrapper Transition
	var trw transitionWrapper
	err := d.DecodeElement(&trw, &startElement)
	if err != nil {
		return err
	}
	*t = Transition(trw)
	t.set = true
	return nil
}

// Validate - validates the "Transition" element
func (t Transition) Validate() error {
	if !t.set {

Extra metadata maintained internally in `xl.meta` for a transitioned object

```
...
        "MetaSys": {
          "x-minio-internal-transition-status": "Y29tcGxldGU=",
          "x-minio-internal-transition-tier": "R0NTVElFUjE=",

--restore-request Days=3
```

### 4.1 Monitoring transition events

`s3:ObjectTransition:Complete` and `s3:ObjectTransition:Failed` events can be used to monitor transition events between the source cluster and transition tier. To watch lifecycle events, you can enable bucket notification on the source bucket with `mc event add`  and specify `--event ilm` flag.

Note that transition event notification is a MinIO extension.

## Explore Further

sleep 10s

## Add warm tier
./mc ilm tier add minio sitea WARM-TIER --endpoint http://localhost:9004 --access-key minioadmin --secret-key minioadmin --bucket bucket

## Add ILM rules
./mc ilm add sitea/bucket --transition-days 0 --transition-tier WARM-TIER
./mc ilm rule list sitea/bucket

./mc cp README.md sitea/bucket/README.md

until $(./mc stat sitea/bucket/README.md --json | jq -r '.metadata."X-Amz-Storage-Class"' | grep -q WARM-TIER); do

	}
	return opts
}

// SetTransitionState sets ILM transition related information from given info.
func (os *objSweeper) SetTransitionState(info TransitionedObject) {
	os.TransitionTier = info.Tier
	os.TransitionStatus = info.Status
	os.RemoteObject = info.Name
	os.TransitionVersionID = info.VersionID
}

// shouldRemoveRemoteObject determines if a transitioned object should be

## TODO

- Richer progress UI is not present at the moment, this will be addressed in subsequent releases. Currently however a RATE of data transfer and usage increase is displayed via `mc`.

  optional int64 observedGeneration = 3;

  // Last time the condition transitioned from one status to another.
  // +required
  optional k8s.io.apimachinery.pkg.apis.meta.v1.Time lastTransitionTime = 4;

  // The reason for the condition's last transition.
  // +required
  optional string reason = 5;

  // A human readable message indicating details about the transition.
  // +required
  optional string message = 6;
}

			expectedErr: errInvalidStorageClass,
		},
		{
			// no transition rule

  // Last time the condition transitioned from one status to another.
  // +optional
  optional k8s.io.apimachinery.pkg.apis.meta.v1.Time lastTransitionTime = 4;

  // Unique, one-word, CamelCase reason for the condition's last transition.
  // +optional
  optional string reason = 5;

  // Human-readable message indicating details about last transition.
  // +optional
  optional string message = 6;
}

	ilmTransitionActiveTasksMD          = NewGaugeMD(transitionActiveTasks, "Number of active ILM transition tasks")
	ilmTransitionPendingTasksMD         = NewGaugeMD(transitionPendingTasks, "Number of pending ILM transition tasks in the queue")
	ilmTransitionMissedImmediateTasksMD = NewCounterMD(transitionMissedImmediateTasks, "Number of missed immediate ILM transition tasks")