* 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 =

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
```

              }

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

Esos detalles son específicos de la implementación.

Para OAuth2 son solo strings.

///

## Vista global { #global-view }

Primero, echemos un vistazo rápido a las partes que cambian desde los ejemplos en el **Tutorial - User Guide** principal para [OAuth2 con Password (y hashing), Bearer con tokens JWT](../../tutorial/security/oauth2-jwt.md). Ahora usando scopes de OAuth2:

## 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**.

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).

   * 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()

import java.util.concurrent.atomic.AtomicInteger;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;

/**
 * Unit test for {@link AbstractService}.
 *
 * @author Jesse Wilson
 */
@NullUnmarked
@GwtIncompatible
@J2ktIncompatible
public class AbstractServiceTest extends TestCase {

  private static final long LONG_TIMEOUT_MILLIS = 10000;
  private Thread executionThread;

import java.util.concurrent.atomic.AtomicInteger;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;

/**
 * Unit test for {@link AbstractService}.
 *
 * @author Jesse Wilson
 */
@NullUnmarked
@GwtIncompatible
@J2ktIncompatible
public class AbstractServiceTest extends TestCase {

  private static final long LONG_TIMEOUT_MILLIS = 10000;
  private Thread executionThread;

import junit.framework.TestSuite;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * Tests for {@link ImmutableSortedMap}.
 *
 * @author Kevin Bourrillion
 * @author Jesse Wilson
 * @author Jared Levy
 */
@GwtCompatible
@SuppressWarnings("AlwaysThrows")
@NullMarked
public class ImmutableSortedMapTest extends TestCase {
  // TODO: Avoid duplicating code in ImmutableMapTest