{
  "message": "Hello World"
}
```

Of course, you will probably find much better ways to take advantage of this than formatting JSON. 😉

## Default response class { #default-response-class }

When creating a **FastAPI** class instance or an `APIRouter` you can specify which response class to use by default.

The parameter that defines this is `default_response_class`.

        assertNotNull(trans2SetFileInfo);
    }

    @Test
    @DisplayName("Test concurrent access")
    void testConcurrentAccess() throws InterruptedException {
        // Setup mock before creating the object
        when(mockFileInfo.getFileInformationLevel()).thenReturn((byte) FileInformation.FILE_BASIC_INFO);
        trans2SetFileInfo = new Trans2SetFileInformation(config, TEST_FID, mockFileInfo);

Alternatively, if you don't have a way to provide a command line option like `--root-path` or equivalent, you can set the `root_path` parameter when creating your FastAPI app:

{* ../../docs_src/behind_a_proxy/tutorial002.py hl[3] *}

Passing the `root_path` to `FastAPI` would be the equivalent of passing the `--root-path` command line option to Uvicorn or Hypercorn.

```

</div>

If you go to the `/docs` API UI, you will see that it is now updated, and it won't expect to receive the `id` from the client when creating a hero, etc.

<div class="screenshot">
<img src="/img/tutorial/sql-databases/image02.png">
</div>

## Recap { #recap }

   */
  public static <E> Builder<E> builderWithExpectedSize(int expectedSize) {
    checkNonnegative(expectedSize, "expectedSize");
    return new Builder<>(expectedSize);
  }

  /**
   * A builder for creating {@code ImmutableSet} instances. Example:
   *
   * {@snippet :
   * static final ImmutableSet<Color> GOOGLE_COLORS =
   *     ImmutableSet.<Color>builder()
   *         .addAll(WEBSAFE_COLORS)

In those cases, several of those entities could have the same ID, let's say `foo` (a user `foo`, a car `foo`, and a blog post `foo`).

So, to avoid ID collisions, when creating the JWT token for the user, you could prefix the value of the `sub` key, e.g. with `username:`. So, in this example, the value of `sub` could have been: `username:johndoe`.

    protected CrawlerContainer crawlerContainer;

    /**
     * Helper for logging crawler activities.
     */
    @Resource
    protected LogHelper logHelper;

    /**
     * Factory for creating crawler clients.
     */
    protected CrawlerClientFactory clientFactory;

    /**
     * Context object containing crawler state and configuration.
     */
    protected CrawlerContext crawlerContext;

También puedes usar `response_model=None` para desactivar la creación de un modelo de response para esa *path operation*, podrías necesitar hacerlo si estás añadiendo anotaciones de tipos para cosas que no son campos válidos de Pydantic, verás un ejemplo de eso en una de las secciones a continuación.

Estamos usando dos puntos (`:`), no igualdades (`=`).

Y agregar anotaciones de tipos normalmente no cambia lo que sucede de lo que ocurriría sin ellas.

Pero ahora, imagina que nuevamente estás en medio de la creación de esa función, pero con anotaciones de tipos.

En el mismo punto, intentas activar el autocompletado con `Ctrl+Espacio` y ves:

<img src="/img/python-types/image02.png">

	queryValue.Set("policy", "")
	return makeTestTargetURL(endPoint, bucketName, "", queryValue)
}

// return URL for creating the bucket.
func getMakeBucketURL(endPoint, bucketName string) string {
	return makeTestTargetURL(endPoint, bucketName, "", url.Values{})
}

// return URL for creating the bucket.
func getBucketVersioningConfigURL(endPoint, bucketName string) string {
	vals := make(url.Values)