Disabled = "Disabled"
	// TransitionStatus status of transition
	TransitionStatus = "transition-status"
	// TransitionedObjectName name of transitioned object
	TransitionedObjectName = "transitioned-object"
	// TransitionedVersionID is version of remote object
	TransitionedVersionID = "transitioned-versionID"
	// TransitionTier name of transition storage class
	TransitionTier = "transition-tier"
)

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 {

     * Called when the service transitions to the {@linkplain State#TERMINATED TERMINATED} state.
     * The {@linkplain State#TERMINATED TERMINATED} state is a terminal state in the transition
     * diagram. Therefore, if this method is called, no other methods will be called on the {@link
     * Listener}.
     *
     * @param from The previous state that is being transitioned from. Failure can occur in any

     * Called when the service transitions to the {@linkplain State#TERMINATED TERMINATED} state.
     * The {@linkplain State#TERMINATED TERMINATED} state is a terminal state in the transition
     * diagram. Therefore, if this method is called, no other methods will be called on the {@link
     * Listener}.
     *
     * @param from The previous state that is being transitioned from. Failure can occur in any

        monitor.leave();
      }
    }

    /**
     * Marks the {@link State} as ready to receive transitions. Returns true if no transitions have
     * been observed yet.
     */
    void markReady() {
      monitor.enter();
      try {
        if (!transitioned) {
          // nothing has transitioned since construction, good.
          ready = true;
        } else {

        monitor.leave();
      }
    }

    /**
     * Marks the {@link State} as ready to receive transitions. Returns true if no transitions have
     * been observed yet.
     */
    void markReady() {
      monitor.enter();
      try {
        if (!transitioned) {
          // nothing has transitioned since construction, good.
          ready = true;
        } else {

}

// ExpectedExpiryTime calculates the expiry, transition or restore date/time based on a object modtime.
// The expected transition or restore time is always a midnight time following the object
// modification time plus the number of transition/restore days.
//
//	e.g. If the object modtime is `Thu May 21 13:42:50 GMT 2020` and the object should
//	    transition in 1 day, then the expected transition time is `Fri, 23 May 2020 00:00:00 GMT`

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