Subclass [EventListener](https://square.github.io/okhttp/3.x/okhttp/okhttp3/EventListener.html) and override methods for the events you are interested in. In a successful HTTP call with no redirects or retries the sequence of events is described by this flow.

![Events Diagram](../assets/images/******@****.***)

{* ../../docs_src/background_tasks/tutorial002_an_py310.py hl[13,15,22,25] *}

Neste exemplo, as mensagens serão escritas no arquivo `log.txt` *após* o envio da resposta.

Se houver uma query na request, ela será registrada em uma tarefa em segundo plano.

// There should be no retries in this function,
// and should have a timeout of something like 2 seconds.
// The returned net.Conn should also have quick disconnect on errors.
// The net.Conn must support all features as described by the net.Conn interface.
type ConnDialer func(ctx context.Context, address string) (net.Conn, error)

// ConnectWSWithRoutePath is like ConnectWS but with a custom grid route path.

* hard dependencies: dependencias obligatorias (do not translate to "dependencias duras")
* locking: locking (do not translate to "bloqueo")
* testing (as in software testing): escribir pruebas (do not translate to "probar")
* code base: code base (do not translate to "base de código")
* default: por defecto (do not translate to "predeterminado")

**FastAPI** tomará ese modelo, generará su JSON Schema y lo incluirá en el lugar correcto en OpenAPI.

Por ejemplo, para declarar otro response con un código de estado `404` y un modelo Pydantic `Message`, puedes escribir:

{* ../../docs_src/additional_responses/tutorial001_py39.py hl[18,22] *}

/// note | Nota

Ten en cuenta que debes devolver el `JSONResponse` directamente.

///

/// info | Información

### Container Images

All container images are available as manifest lists and support the described
architectures. It is also possible to pull a specific architecture directly by
adding the "-$ARCH" suffix  to the container image name.

name | architectures
---- | -------------

         * repository's layout to allow pointing at artifacts within the repository. Unfortunately,
         * DefaultRepositoryLayout does not correctly describe the layout of a local repository which unlike a remote
         * repository never uses timestamps in the filename of a snapshot artifact. The discrepancy gets notable when a

Así que, continuando con el `user_dict` anterior, escribir:

```Python
UserInDB(**user_dict)
```

sería equivalente a algo como:

```Python
UserInDB(
    username="john",
    password="secret",
    email="******@****.***",
    full_name=None,

### Container Images

All container images are available as manifest lists and support the described
architectures. It is also possible to pull a specific architecture directly by
adding the "-$ARCH" suffix  to the container image name.

name | architectures
---- | -------------

## Alternative Events (deprecated) { #alternative-events-deprecated }

/// warning

The recommended way to handle the *startup* and *shutdown* is using the `lifespan` parameter of the `FastAPI` app as described above. If you provide a `lifespan` parameter, `startup` and `shutdown` event handlers will no longer be called. It's all `lifespan` or all events, not both.

You can probably skip this part.

///