*
     * @return an {@link Optional} containing the boolean flag, or empty if not set
     */
    @Nonnull
    Optional<Boolean> verbose();

    /**
     * Indicates whether to show error stack traces.
     *
     * @return an {@link Optional} containing the boolean flag, or empty if not set
     */
    @Nonnull
    Optional<Boolean> showErrors();

    /**

    // cause system property.  This allows us to run with both settings of the property in one jvm
    // without resorting to even crazier hacks to reset static final boolean fields.
    System.setProperty("guava.concurrent.generate_cancellation_cause", "true");
    String concurrentPackage = SettableFuture.class.getPackage().getName();
    classReloader =

    // cause system property.  This allows us to run with both settings of the property in one jvm
    // without resorting to even crazier hacks to reset static final boolean fields.
    System.setProperty("guava.concurrent.generate_cancellation_cause", "true");
    String concurrentPackage = SettableFuture.class.getPackage().getName();
    classReloader =

      try {
        checkCurrentState(RUNNING);
      } finally {
        monitor.leave();
      }
    } else {
      // It is possible due to races that we are currently in the expected state even though we
      // timed out. e.g. if we weren't event able to grab the lock within the timeout we would never

Doing that in separated functions that don't share logic or variables together is more difficult as you would need to store values in global variables or similar tricks.

Because of that, it's now recommended to instead use the `lifespan` as explained above.

## Technical Details { #technical-details }

Just a technical detail for the curious nerds. 🤓

# Testando

Graças ao <a href="https://www.starlette.io/testclient/" class="external-link" target="_blank">Starlette</a>, testar aplicativos **FastAPI** é fácil e agradável.

Ele é baseado no <a href="https://www.python-httpx.org" class="external-link" target="_blank">HTTPX</a>, que por sua vez é projetado com base em Requests, por isso é muito familiar e intuitivo.

    private transient Object lock = new Object();

    final Supplier<T> delegate;
    transient volatile boolean initialized;
    // "value" does not need to be volatile; visibility piggy-backs
    // on volatile read of "initialized".
    transient @Nullable T value;

    MemoizingSupplier(Supplier<T> delegate) {
      this.delegate = checkNotNull(delegate);
    }

    @Override

# Corpo - Modelos aninhados

Com o **FastAPI**, você pode definir, validar, documentar e usar modelos profundamente aninhados de forma arbitrária (graças ao Pydantic).

## Campos do tipo Lista

Você pode definir um atributo como um subtipo. Por exemplo, uma `list` do Python:

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

Isso fará com que tags seja uma lista de itens mesmo sem declarar o tipo dos elementos desta lista.

    private transient Object lock = new Object();

    final Supplier<T> delegate;
    transient volatile boolean initialized;
    // "value" does not need to be volatile; visibility piggy-backs
    // on volatile read of "initialized".
    transient @Nullable T value;

    MemoizingSupplier(Supplier<T> delegate) {
      this.delegate = checkNotNull(delegate);
    }

    @Override

    @JvmField
    val EMPTY: RequestBody = ByteString.EMPTY.toRequestBody()

    /**
     * Returns a new request body that transmits this string. If [contentType] is non-null and lacks
     * a charset, this will use UTF-8.
     */
    @JvmStatic
    @JvmName("create")
    fun String.toRequestBody(contentType: MediaType? = null): RequestBody {