### `shutdown`-Event

Um eine Funktion hinzuzufügen, die beim Herunterfahren der Anwendung ausgeführt werden soll, deklarieren Sie sie mit dem Event `shutdown`:

{* ../../docs_src/events/tutorial002.py hl[6] *}

Hier schreibt die `shutdown`-Eventhandler-Funktion eine Textzeile `"Application shutdown"` in eine Datei `log.txt`.

/// info

# Testing Events: startup - shutdown

Cuando necesitas que tus manejadores de eventos (`startup` y `shutdown`) se ejecuten en tus tests, puedes usar el `TestClient` con un statement `with`:

            lock.writeLock().unlock();
        }
    }

    /**
     * Shuts down the persistent handle manager and its background tasks
     */
    public void shutdown() {
        shutdown = true;
        scheduler.shutdown();
    }

    }

    @Test
    void testShutdown() {
        assertDoesNotThrow(() -> channelManager.shutdown());

        // Multiple shutdowns should be safe
        assertDoesNotThrow(() -> channelManager.shutdown());
    }

    @Test
    void testLoadBalancerAccess() {
        ChannelLoadBalancer balancer = channelManager.getLoadBalancer();

        startLatch.countDown();

        // Wait for completion
        assertTrue(endLatch.await(30, TimeUnit.SECONDS), "All threads should complete within timeout");
        executor.shutdown();

        // Then - Verify no exceptions occurred
        if (!exceptions.isEmpty()) {
            fail("Concurrent operations caused exceptions: " + exceptions.get(0));
        }

  /** Simple same thread listening executor service that doesn't handle shutdown. */
  private static class TestListeningExecutorService extends AbstractListeningExecutorService {

    @Override
    public void execute(Runnable runnable) {
      assertThat(runnable).isInstanceOf(TrustedListenableFutureTask.class);
      runnable.run();
    }

    @Override
    public void shutdown() {}

    @Override
    public List<Runnable> shutdownNow() {

  /** Simple same thread listening executor service that doesn't handle shutdown. */
  private static class TestListeningExecutorService extends AbstractListeningExecutorService {

    @Override
    public void execute(Runnable runnable) {
      assertThat(runnable).isInstanceOf(TrustedListenableFutureTask.class);
      runnable.run();
    }

    @Override
    public void shutdown() {}

    @Override
    public List<Runnable> shutdownNow() {

            return defaultCreds;
        }

        @Override
        public boolean close() throws CIFSException {
            closeCalled = true;
            // Call super.close() to ensure the shutdown hook is removed
            return super.close();
        }

        public boolean isCloseCalled() {
            return closeCalled;
        }

        @Override

            changeNotifier.stopWatching(directoryPath);
            baseLeaseManager.releaseLease(entry.getLeaseKey());
        }
    }

    /**
     * Shutdown the directory lease manager
     */
    public void shutdown() {
        scheduler.shutdown();
        try {
            if (!scheduler.awaitTermination(5, TimeUnit.SECONDS)) {
                scheduler.shutdownNow();
            }

    Request request = new Request.Builder()
        .url("ws://echo.websocket.org")
        .build();
    client.newWebSocket(request, this);

    // Trigger shutdown of the dispatcher's executor so this process exits immediately.
    client.dispatcher().executorService().shutdown();
  }

  @Override public void onOpen(WebSocket webSocket, Response response) {
    webSocket.send("Hello...");
    webSocket.send("...World!");