type GetObjectContext struct {
	OutputRoute string `json:"outputRoute"`
	OutputToken string `json:"outputToken"`
	InputS3URL  string `json:"inputS3Url"`
}

// Event represents lambda function event, this is undocumented in AWS S3. This
// structure bases itself on this structure but there is no binding.
//
//	{
//	  "xAmzRequestId": "a2871150-1df5-4dc9-ad9f-3da283ca1bf3",
//	  "getObjectContext": {
//	    "outputRoute": "...",

	UserAgent    string
}

// ToEvent - converts to notification event.
func (args eventArgs) ToEvent(escape bool) event.Event {
	eventTime := UTCNow()
	uniqueID := fmt.Sprintf("%X", eventTime.UnixNano())
	if !args.Object.ModTime.IsZero() {
		uniqueID = fmt.Sprintf("%X", args.Object.ModTime.UnixNano())
	}

	respElements := map[string]string{
		"x-amz-request-id": args.RespElements["requestId"],

In this case, the `startup` event handler function will initialize the items "database" (just a `dict`) with some values.

You can add more than one event handler function.

And your application won't start receiving requests until all the `startup` event handlers have completed.

### `shutdown` event { #shutdown-event }

To add a function that should be run when the application is shutting down, declare it with the event `"shutdown"`:

首先要注意的是，我们定义了一个带有 `yield` 的异步函数。这与带有 `yield` 的依赖项非常相似。

```Python hl_lines="14-19"
{!../../docs_src/events/tutorial003.py!}
```

这个函数在 `yield`之前的部分，会在应用启动前执行。

剩下的部分在 `yield` 之后，会在应用完成后执行。

## 异步上下文管理器

如你所见，这个函数有一个装饰器 `@asynccontextmanager` 。

它将函数转化为所谓的“**异步上下文管理器**”。

```Python hl_lines="1  13"
{!../../docs_src/events/tutorial003.py!}
```

在 Python 中，  **上下文管理器**是一个你可以在 `with` 语句中使用的东西，例如，`open()` 可以作为上下文管理器使用。

![Events Diagram](../assets/images/events@2x.png)

Here’s a [sample event listener](https://github.com/square/okhttp/blob/master/samples/guide/src/main/java/okhttp3/recipes/PrintEventsNonConcurrent.java) that prints each event with a timestamp.

```java

# Testing Events: lifespan and startup - shutdown { #testing-events-lifespan-and-startup-shutdown }

When you need `lifespan` to run in your tests, you can use the `TestClient` with a `with` statement:

{* ../../docs_src/app_testing/tutorial004_py39.py hl[9:15,18,27:28,30:32,41:43] *}


You can read more details about the ["Running lifespan in tests in the official Starlette documentation site."](https://www.starlette.dev/lifespan/#running-lifespan-in-tests)

events@2x.png...

Estas funciones pueden ser declaradas con `async def` o `def` normal.

### Evento `startup` { #startup-event }

Para añadir una función que debería ejecutarse antes de que la aplicación inicie, declárala con el evento `"startup"`:

{* ../../docs_src/events/tutorial001_py39.py hl[8] *}

En este caso, la función manejadora del evento `startup` inicializará los ítems de la "base de datos" (solo un `dict`) con algunos valores.

          }
        };

    @Override
    void dispatch(Object event, Iterator<Subscriber> subscribers) {
      checkNotNull(event);
      checkNotNull(subscribers);
      // requireNonNull accommodates Android's @RecentlyNullable annotation on ThreadLocal.get
      Queue<Event> queueForThread = requireNonNull(queue.get());
      queueForThread.offer(new Event(event, subscribers));

      if (!dispatching.get()) {

	}
	globalTransitionState.queueTransitionTask(obj, event, src)
	return true
}

func applyExpiryOnTransitionedObject(ctx context.Context, objLayer ObjectLayer, obj ObjectInfo, lcEvent lifecycle.Event, src lcEventSrc) (ok bool) {
	timeILM := globalScannerMetrics.timeILM(lcEvent.Action)
	if err := expireTransitionedObject(ctx, objLayer, &obj, lcEvent, src); err != nil {
		if isErrObjectNotFound(err) || isErrVersionNotFound(err) {