## Ajouter une tâche d'arrière-plan

Dans votre *fonction de chemin*, passez votre fonction de tâche à l'objet de type `BackgroundTasks` (`background_tasks` ici) grâce à la méthode `.add_task()` :


{* ../../docs_src/background_tasks/tutorial001.py hl[14] *}

`.add_task()` reçoit comme arguments :

* Une fonction de tâche à exécuter en arrière-plan (`write_notification`).

    # - - - - - - - - - -/

    # /- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
    # o isAvailableDatabaseDependency: (NotRequired - Default false)
    #   [true]
    #     Generate the method that depends on the database. e.g. cb.lockWithRR() at DB2.
    #
    #; isAvailableDatabaseDependency = false
    # - - - - - - - - - -/

    # /- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

            StackOverflowError.class,
            e -> e instanceof StackOverflowError);
      }
    };

    // used under GWT, etc., since the override of this method does not exist there
    ImmutableMap<Class<? extends Throwable>, Predicate<Throwable>> exceptions() {
      return ImmutableMap.of();
    }
  }

    return tempFile;
  }

  /**
   * Gets a temp dir for testing. The returned directory and all contents of it will be deleted in
   * the tear-down for this test. Subsequent invocations of this method will return the same
   * directory.
   */
  protected final File getTempDir() throws IOException {
    if (tempDir == null) {
      tempDir = createTempDir();
    }

    return tempDir;
  }

`CORSMiddleware` отвечает на два типа HTTP-запросов...

### CORS-запросы с предварительной проверкой

Это любые `OPTIONS` запросы с заголовками `Origin` и `Access-Control-Request-Method`.

В этом случае middleware перехватит входящий запрос и отправит соответствующие CORS-заголовки в ответе, а также ответ `200` или `400` в информационных целях.

### Простые запросы

  /**
   * Converts the specified {@code String str} from this format to the specified {@code format}. A
   * "best effort" approach is taken; if {@code str} does not conform to the assumed format, then
   * the behavior of this method is undefined but we make a reasonable effort at converting anyway.
   */
  public final String to(CaseFormat format, String str) {
    checkNotNull(format);
    checkNotNull(str);

     * {@link #build(ModelBuildingRequest)} with {@link ModelBuildingRequest#isTwoPhaseBuilding()} being {@code true}.
     * The model building request passed to this method must be the same as the one used for the first phase of the
     * model building.
     *
     * @param request The model building request that holds the parameters, must not be {@code null}.

            "",
            display = ParameterDisplay.PROMPT,
            allowEmpty = false,
            description = "Which performance test to run. Should be the fully qualified class name dot (unrolled) method name. E.g. org.gradle.performance.regression.java.JavaUpToDatePerformanceTest.up-to-date assemble (parallel true)"
        )

    init(subjectGenerator, suiteName, null, null);
  }

  public G getSubjectGenerator() {
    return subjectGenerator;
  }

  /** Returns the name of the test method invoked by this test instance. */
  @J2ktIncompatible
  @GwtIncompatible // not used under GWT, and super.getName() is not available under J2CL
  public final String getTestMethodName() {
    return super.getName();
  }

    init(subjectGenerator, suiteName, null, null);
  }

  public G getSubjectGenerator() {
    return subjectGenerator;
  }

  /** Returns the name of the test method invoked by this test instance. */
  @J2ktIncompatible
  @GwtIncompatible // not used under GWT, and super.getName() is not available under J2CL
  public final String getTestMethodName() {
    return super.getName();
  }