We are going to start from where we left in the previous chapter and increment it.

## About JWT { #about-jwt }

JWT means "JSON Web Tokens".

It's a standard to codify a JSON object in a long dense string without spaces. It looks like this:

```
eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c
```

   * test makes a single call with two duplex requests!
   */
  @Test
  fun duplexWithAuthChallenge() {
    enableProtocol(Protocol.HTTP_2)
    val credential = basic("jesse", "secret")
    client =
      client
        .newBuilder()
        .authenticator(RecordingOkAuthenticator(credential, null))
        .build()
    val body1 =
      MockSocketHandler()

Der `scopes`-Parameter erhält ein <abbr title="Dictionary – Zuordnungstabelle: In anderen Sprachen auch Hash, Map, Objekt, Assoziatives Array genannt">`dict`</abbr> mit jedem Scope als Schlüssel und dessen Beschreibung als Wert:

{* ../../docs_src/security/tutorial005_an_py310.py hl[63:66] *}

Da wir diese Scopes jetzt deklarieren, werden sie in der API-Dokumentation angezeigt, wenn Sie sich einloggen/autorisieren.

 * callbacks. Its subclasses must manage threads manually; consider {@link
 * AbstractExecutionThreadService} if you need only a single execution thread.
 *
 * @author Jesse Wilson
 * @author Luke Sandberg
 * @since 1.0
 */
@GwtIncompatible
@J2ktIncompatible
public abstract class AbstractService implements Service {
  private static final ListenerCallQueue.Event<Listener> STARTING_EVENT =

              }

              println("Authenticating for response: $response")
              println("Challenges: ${response.challenges()}")
              val credential = Credentials.basic("jesse", "password1")
              return response.request.newBuilder()
                  .header("Authorization", credential)
                  .build()
            }
          })
          .build()

Estes escopos representam "permissões".

No OpenAPI (e.g. os documentos da API), você pode definir "esquemas de segurança".

Quando um desses esquemas de segurança utiliza OAuth2, você pode também declarar e utilizar escopos.

Cada "escopo" é apenas uma string (sem espaços).

 * Second, it is always backed by an array large enough to hold a value for every possible
 * combination of row and column keys. (This is rarely optimal unless the table is extremely dense.)
 * Finally, every possible combination of row and column keys is always considered to have a value
 * associated with it: It is not possible to "remove" a value, only to replace it with {@code null},

<a href="https://github.com/containous/traefik/releases" class="external-link" target="_blank">Descarga Traefik</a>, es un archivo binario único, puedes extraer el archivo comprimido y ejecutarlo directamente desde la terminal.

Luego crea un archivo `traefik.toml` con:

```TOML hl_lines="3"
[entryPoints]
  [entryPoints.http]
    address = ":9999"

[providers]
  [providers.file]

## Tipo de Retorno y Filtrado de Datos { #return-type-and-data-filtering }

Continuemos con el ejemplo anterior. Queríamos **anotar la función con un tipo**, pero queríamos poder devolver desde la función algo que en realidad incluya **más datos**.

 * Second, it is always backed by an array large enough to hold a value for every possible
 * combination of row and column keys. (This is rarely optimal unless the table is extremely dense.)
 * Finally, every possible combination of row and column keys is always considered to have a value
 * associated with it: It is not possible to "remove" a value, only to replace it with {@code null},