Collection<V> unmodifiableEmptyCollection() {
    if (unfiltered instanceof SetMultimap) {
      return emptySet();
    } else {
      return emptyList();
    }
  }

  @Override
  public void clear() {
    keySet().clear();
  }

  @Override
  Set<K> createKeySet() {
    return Sets.filter(unfiltered.keySet(), keyPredicate);
  }

  @Override
  public Collection<V> get(@ParametricNullness K key) {

  Collection<V> unmodifiableEmptyCollection() {
    if (unfiltered instanceof SetMultimap) {
      return emptySet();
    } else {
      return emptyList();
    }
  }

  @Override
  public void clear() {
    keySet().clear();
  }

  @Override
  Set<K> createKeySet() {
    return Sets.filter(unfiltered.keySet(), keyPredicate);
  }

  @Override
  public Collection<V> get(@ParametricNullness K key) {

        return Collections.unmodifiableSet(whitelistedPaths);
    }

    /**
     * Clear all blacklisted paths
     */
    public void clearBlacklist() {
        blacklistedPaths.clear();
    }

    /**
     * Clear all whitelisted paths
     */
    public void clearWhitelist() {
        whitelistedPaths.clear();
    }

      assertTrue(Thread.holdsLock(mutex));
      return delegate.retainAll(collection);
    }

    @Override
    public void clear() {
      assertTrue(Thread.holdsLock(mutex));
      delegate.clear();
    }

    @Override
    public Object[] toArray() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.toArray();
    }

    @Override

   * clear()} clears all table mappings.
   */
  @WeakOuter
  private abstract class TableSet<T> extends ImprovedAbstractSet<T> {
    @Override
    public boolean isEmpty() {
      return backingMap.isEmpty();
    }

    @Override
    public void clear() {
      backingMap.clear();
    }
  }

  /**
   * {@inheritDoc}
   *

Se houver alguma tarefa em segundo plano (documentada posteriormente), ela será executada *depois* de todo o middleware.

///

## Criar um middleware

Para criar um middleware, use o decorador `@app.middleware("http")` logo acima de uma função.

A função middleware recebe:

* A `request`.
* Uma função `call_next` que receberá o `request` como um parâmetro.

    }

    /**
     * @throws Exception
     */
    @Test
    public void testClear() throws Exception {
        final BeanDesc beanDesc = BeanDescFactory.getBeanDesc(MyBean.class);
        BeanDescFactory.clear();
        assertThat(BeanDescFactory.getBeanDesc(MyBean.class), is(not(sameInstance(beanDesc))));
    }

    /**
     *
     */
    public static class MyBean {

        /**
         * @return String

    }

    @Override
    public boolean contains(@Nullable Object o) {
      return AbstractMultimap.this.containsValue(o);
    }

    @Override
    public void clear() {
      AbstractMultimap.this.clear();
    }
  }

  Iterator<V> valueIterator() {
    return Maps.valueIterator(entries().iterator());
  }

  @LazyInit private transient @Nullable Map<K, Collection<V>> asMap;

{* ../../docs_src/background_tasks/tutorial001.py hl[1,13] *}

**FastAPI** créera l'objet de type `BackgroundTasks` pour vous et le passera comme paramètre.

## Créer une fonction de tâche

Une fonction à exécuter comme tâche d'arrière-plan est juste une fonction standard qui peut recevoir des paramètres.

  @Override
  protected abstract Multimap<K, V> delegate();

  @Override
  public Map<K, Collection<V>> asMap() {
    return delegate().asMap();
  }

  @Override
  public void clear() {
    delegate().clear();
  }

  @Override
  public boolean containsEntry(@Nullable Object key, @Nullable Object value) {
    return delegate().containsEntry(key, value);
  }

  @Override