In this example, when the client requests an item by an ID that doesn't exist, raise an exception with a status code of `404`:

{* ../../docs_src/handling_errors/tutorial001_py39.py hl[11] *}

### The resulting response { #the-resulting-response }

If the client requests `http://example.com/items/foo` (an `item_id` `"foo"`), that client will receive an HTTP status code of 200, and a JSON response of:

```JSON
{
  "item": "The Foo Wrestlers"

 * Returns a new provider that takes its value from at most one
 * of the given providers. If no input provider is present, the output
 * provider will not be present. If more than one input provider
 * has a value specified, the resulting provider will throw an
 * exception when queried.
 */
fun <T: Any> atMostOneOf(vararg providers: Provider<T>): Provider<T> {
    return providers.map { provider ->
        provider.map {
            Optional.of(it)

If you open the automatic API docs, your extension will show up at the bottom of the specific *path operation*.

<img src="/img/tutorial/path-operation-advanced-configuration/image01.png">

And if you see the resulting OpenAPI (at `/openapi.json` in your API), you will see your extension as part of the specific *path operation* too:

```JSON hl_lines="22"
{
    "openapi": "3.1.0",
    "info": {
        "title": "FastAPI",

В данном примере, когда клиент запрашивает элемент по несуществующему ID, возникает исключение со статус-кодом `404`:

{* ../../docs_src/handling_errors/tutorial001_py39.py hl[11] *}

### Возвращаемый ответ { #the-resulting-response }

Если клиент запросит `http://example.com/items/foo` (`item_id` `"foo"`), то он получит статус-код 200 и ответ в формате JSON:

```JSON
{
  "item": "The Foo Wrestlers"
}
```

{* ../../docs_src/handling_errors/tutorial001_py39.py hl[11] *}

### Die resultierende Response { #the-resulting-response }

Wenn der Client `http://example.com/items/foo` anfordert (ein `item_id` `"foo"`), erhält dieser Client einen HTTP-Statuscode 200 und diese JSON-Response:

```JSON
{
  "item": "The Foo Wrestlers"
}
```

Neste exemplo, quando o cliente pede, na requisição, por um item cujo ID não existe, a exceção com o status code `404` é lançada:

{* ../../docs_src/handling_errors/tutorial001_py39.py hl[11] *}

### A response resultante { #the-resulting-response }

Se o cliente faz uma requisição para `http://example.com/items/foo` (um `item_id` `"foo"`), esse cliente receberá um HTTP status code 200, e uma resposta JSON:


```JSON
{
  "item": "The Foo Wrestlers"

En este ejemplo, cuando el cliente solicita un ítem por un ID que no existe, lanza una excepción con un código de estado de `404`:

{* ../../docs_src/handling_errors/tutorial001_py39.py hl[11] *}

### El response resultante { #the-resulting-response }

Si el cliente solicita `http://example.com/items/foo` (un `item_id` `"foo"`), ese cliente recibirá un código de estado HTTP de 200, y un response JSON de:

```JSON
{
  "item": "The Foo Wrestlers"
}

     * try to merge the element data, rather than putting the dominant and recessive elements (which share the same
     * element name) as siblings in the resulting DOM.
     */
    @Deprecated(since = "4.0.0", forRemoval = true)
    String DEFAULT_CHILDREN_COMBINATION_MODE = XmlService.DEFAULT_CHILDREN_COMBINATION_MODE;

    @Deprecated(since = "4.0.0", forRemoval = true)

 * retrieved from the artifact descriptor of the root dependency. And last, only direct dependencies can be specified in
 * which case the root node of the resulting graph has no associated dependency.
 *
 * @since 4.0.0
 */
@Experimental
@Immutable
public interface DependencyResolverRequest extends RepositoryAwareRequest {

    enum RequestType {
        COLLECT,

Then you create an instance of that class with some values and it will validate the values, convert them to the appropriate type (if that's the case) and give you an object with all the data.

And you get all the editor support with that resulting object.

An example from the official Pydantic docs:

{* ../../docs_src/python_types/tutorial011_py310.py *}

/// info