## Tipos especiales y validación { #special-types-and-validation }

Además de tipos singulares normales como `str`, `int`, `float`, etc., puedes usar tipos singulares más complejos que heredan de `str`.

Para ver todas las opciones que tienes, revisa el <a href="https://docs.pydantic.dev/latest/concepts/types/" class="external-link" target="_blank">Overview de Tipos de Pydantic</a>. Verás algunos ejemplos en el siguiente capítulo.

     * where the property value is defined.
     */
    enum Source {
        /**
         * Maven system properties. These properties are evaluated very early during the boot process,
         * typically set by Maven itself and flagged as readOnly=true or by users via maven-system.properties files.

   * tiny bit of syntactic sugar for {@code new ArrayList<>(}{@link Arrays#asList asList}{@code
   * (...))}, or for creating an empty list then calling {@link Collections#addAll}. This method is
   * not actually very useful.
   */
  @SafeVarargs
  @SuppressWarnings("NonApiType") // acts as a direct substitute for a constructor call
  public static <E extends @Nullable Object> ArrayList<E> newArrayList(E... elements) {

E essa função vai receber os parâmetros da mesma forma que uma *função de operação de rota*.

/// tip | Dica

Você verá quais outras "coisas", além de funções, podem ser usadas como dependências no próximo capítulo.

///

Sempre que uma nova requisição for realizada, o **FastAPI** se encarrega de:

 *
 * Build up a collection by starting with [EmptyTags] and repeatedly calling [plus]. Each such call
 * returns a new instance.
 *
 * This collection is optimized for safe concurrent access over a very small number of elements.
 *
 * This collection and is expected to hold fewer than 10 elements. Each operation is _O(N)_, and so
 * building an instance with _N_ elements is _O(N**2)_.
 */
internal sealed class Tags {

### Confira a documentação { #check-the-docs }

Agora você pode iniciar a sua aplicação e ir até <a href="http://127.0.0.1:8000/docs" class="external-link" target="_blank">http://127.0.0.1:8000/docs</a>.

Você verá que a sua documentação possui as *operações de rota* normais e agora também possui alguns **webhooks**:

///

## Forbid Extra Cookies { #forbid-extra-cookies }

In some special use cases (probably not very common), you might want to **restrict** the cookies that you want to receive.

In this case, you have:

* `ItemsService`
* `UsersService`

### Client Method Names { #client-method-names }

Right now, the generated method names like `createItemItemsPost` don't look very clean:

```TypeScript
ItemsService.createItemItemsPost({name: "Plumbus", price: 5})
```

...that's because the client generator uses the OpenAPI internal **operation ID** for each *path operation*.

///

## Upgrading the FastAPI versions { #upgrading-the-fastapi-versions }

You should add tests for your app.

With **FastAPI** it's very easy (thanks to Starlette), check the docs: [Testing](../tutorial/testing.md){.internal-link target=_blank}

    data = {
        "name": "Special Offer",
        "description": "This is a special offer",
        "price": 38.6,
        "items": [
            {
                "name": "Foo",
                "description": "A very nice Item",
                "price": 35.4,
                "tax": 3.2,
                "tags": ["foo"],
                "images": [
                    {
                        "url": "http://example.com/image.png",