}

  /** Identifies just tryEnterXxx methods (a subset of {@link #isAnyEnter}), which never block. */
  private static boolean isTryEnter(Method method) {
    return method.getName().startsWith("tryEnter");
  }

  /**
   * Identifies just enterIfXxx methods (a subset of {@link #isAnyEnter}), which are mostly like the

This example doesn't implement the callback itself (that could be just a line of code), only the documentation part.

/// tip

The actual callback is just an HTTP request.

Do you want to just have a `str`? Or just a `dict`? Or a database class model instance directly? It all works the same way.

You actually don't have users that log in to your application but robots, bots, or other systems, that have just an access token? Again, it all works the same.

Each "scope" is just a string (without spaces).

They are normally used to declare specific security permissions, for example:

* `users:read` or `users:write` are common examples.
* `instagram_basic` is used by Facebook / Instagram.
* `https://www.googleapis.com/auth/drive` is used by Google.

/// info

In OAuth2 a "scope" is just a string that declares a specific permission required.

@Experimental
@Consumer
@Named
public interface ModelTransformer extends SpiService {

    /**
     * Apply a transformation on the file model.
     *
     * This method will be called on each file model being loaded,
     * just before validation.
     *
     * @param model the input model
     * @return the transformed model, or the input model if no transformation is needed
     * @throws ModelTransformerException
     */
    @Nonnull

///

/// note | "Technical Details"

You could also use `from starlette.testclient import TestClient`.

**FastAPI** provides the same `starlette.testclient` as `fastapi.testclient` just as a convenience for you, the developer. But it comes directly from Starlette.

///

/// tip

Each "scope" is just a string (without spaces).

They are normally used to declare specific security permissions, for example:

* `users:read` or `users:write` are common examples.
* `instagram_basic` is used by Facebook / Instagram.
* `https://www.googleapis.com/auth/drive` is used by Google.

/// info

In OAuth2 a "scope" is just a string that declares a specific permission required.

## Response with arbitrary `dict`

You can also declare a response using a plain arbitrary `dict`, declaring just the type of the keys and values, without using a Pydantic model.

This is useful if you don't know the valid field/attribute names (that would be needed for a Pydantic model) beforehand.

In this case, you can use `typing.Dict` (or just `dict` in Python 3.9 and above):

//// tab | Python 3.9+

```Python hl_lines="6"

That doesn't add any extra security to your API, the *path operations* will still be available where they are.

If there's a security flaw in your code, it will still exist.

Si vous ne voulez pas leur donner de valeur par défaut mais juste les rendre optionnels, utilisez `None` comme valeur par défaut.

Mais si vous voulez rendre un paramètre de requête obligatoire, vous pouvez juste ne pas y affecter de valeur par défaut :

{* ../../docs_src/query_params/tutorial005.py hl[6:7] *}