* }</pre>
 *
 * <p>Graph algorithms that need additional capabilities (accessing both predecessors and
 * successors, iterating over the edges, etc.) should declare their input to be of a type that
 * provides those capabilities, such as {@link Graph}, {@link ValueGraph}, or {@link Network}.
 *
 * <h3>Additional documentation</h3>
 *

And it's also used internally when mounting sub-applications.

## Proxy with a stripped path prefix

Having a proxy with a stripped path prefix, in this case, means that you could declare a path at `/app` in your code, but then, you add a layer on top (the proxy) that would put your **FastAPI** application under a path like `/api/v1`.

In this case, the original path `/app` would actually be served at `/api/v1/app`.

Vous pouvez déclarer le type d'un paramètre de chemin dans la fonction, en utilisant les annotations de type Python :


```Python hl_lines="7"
{!../../docs_src/path_params/tutorial002.py!}
```

Ici, `item_id` est déclaré comme `int`.

/// check | "vérifier"

Ceci vous permettra d'obtenir des fonctionnalités de l'éditeur dans votre fonction, telles
que des vérifications d'erreur, de l'auto-complétion, etc.

///

Consiste apenas de funções que parecem idênticas a *funções de operação de rota*.

Mas ainda assim, é bastante poderoso, e permite que você declare grafos (árvores) de dependências com uma profundidade arbitrária.

/// tip | "Dica"

Tudo isso pode não parecer muito útil com esses exemplos.

Mas você verá o quão útil isso é nos capítulos sobre **segurança**.

## Utiliser `BackgroundTasks`

Pour commencer, importez `BackgroundTasks` et définissez un paramètre dans votre *fonction de chemin* avec `BackgroundTasks` comme type déclaré.

{* ../../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

Se você estiver utilizando bibliotecas de terceiros que dizem para você chamar as funções com `await`, como:

```Python
results = await some_library()
```

Então, declare sua *função de operação de rota* com `async def` como:

```Python hl_lines="2"
@app.get('/')
async def read_results():
    results = await some_library()
    return results
```

/// note

 * @see org.apache.maven.api.model.Dependency#getScope()
 * @see org.apache.maven.api.services.DependencyResolver
 */
@Experimental
@Immutable
public enum DependencyScope {

    /**
     * None. Allows you to declare dependencies (for example to alter reactor build order) but in reality dependencies
     * in this scope are not part of any path scope.
     */
    NONE("none", false),

    /**

<abbr title="too long; didn't read"><strong>TL;DR:</strong></abbr>

If you are using third party libraries that tell you to call them with `await`, like:

```Python
results = await some_library()
```

Then, declare your *path operation functions* with `async def` like:

```Python hl_lines="2"
@app.get('/')
async def read_results():
    results = await some_library()
    return results
```

/// note

 * }</pre>
 *
 * <p>Graph algorithms that need additional capabilities (accessing both predecessors and
 * successors, iterating over the edges, etc.) should declare their input to be of a type that
 * provides those capabilities, such as {@link Graph}, {@link ValueGraph}, or {@link Network}.
 *
 * <h3>Additional documentation</h3>
 *

import javax.lang.model.element.Modifier;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Tester of subtyping relationships between two types.
 *
 * <p>Tests should inherit from this class, and declare subtyping relationship with public methods
 * annotated by {@link TestSubtype}.
 *
 * <p>These declaration methods rely on Java static type checking to make sure what we want to