<div class="screenshot">
<img src="/img/tutorial/separate-openapi-schemas/image02.png">
</div>

Esto significa que **siempre tendrá un valor**, solo que a veces el valor podría ser `None` (o `null` en JSON).

Eso significa que, los clientes que usan tu API no tienen que comprobar si el valor existe o no, pueden **asumir que el campo siempre estará allí**, pero solo que en algunos casos tendrá el valor por defecto de `None`.

   *
   * <ul>
   *   <li>The non-private constructor or non-private static factory method with the most parameters
   *       is used to construct the sample instances. In case of tie, the candidate constructors or
   *       factories are tried one after another until one can be used to construct sample
   *       instances.
   *   <li>For the constructor or static factory method used to construct instances, it's checked

<img src="/img/tutorial/separate-openapi-schemas/image02.png">
</div>

Isso significa que ele **sempre terá um valor**, só que às vezes o valor pode ser `None` (ou `null` em termos de JSON).

Isso quer dizer que, os clientes que usam sua API não precisam verificar se o valor existe ou não, eles podem **assumir que o campo sempre estará lá**, mas que em alguns casos terá o valor padrão de `None`.

  /**
   * Opens a new buffered {@link OutputStream} for writing to this sink. The returned stream is not
   * required to be a {@link BufferedOutputStream} in order to allow implementations to simply
   * delegate to {@link #openStream()} when the stream returned by that method does not benefit from
   * additional buffering (for example, a {@code ByteArrayOutputStream}). This method returns a new,

  /**
   * Opens a new buffered {@link OutputStream} for writing to this sink. The returned stream is not
   * required to be a {@link BufferedOutputStream} in order to allow implementations to simply
   * delegate to {@link #openStream()} when the stream returned by that method does not benefit from
   * additional buffering (for example, a {@code ByteArrayOutputStream}). This method returns a new,

O `TestClient` é baseado no <a href="https://www.python-httpx.org" class="external-link" target="_blank">HTTPX</a>, e felizmente nós podemos utilizá-lo diretamente para testar a API.

## Exemplo

Para um exemplos simples, vamos considerar uma estrutura de arquivos semelhante ao descrito em [Bigger Applications](../tutorial/bigger-applications.md){.internal-link target=_blank} e [Testing](../tutorial/testing.md){.internal-link target=_blank}:

```
.

- ObjectType (default)
- LegacyObjectType (preserves existing deployments and older xl.json format)
- DeleteMarker (a versionId to capture the DELETE sequences implemented primarily for AWS spec compatibility)

A sample msgpack-JSON `xl.meta`, you can debug the content inside `xl.meta` using [xl-meta.go](https://github.com/minio/minio/tree/master/docs/debugging#decoding-metadata) program.

```json
{
  "Versions": [
    {
      "Type": 1,

 *
 * @since 4.0.0
 * @see org.apache.maven.api.services.DependencyResolver
 * @see DependencyScope
 */
@Experimental
@Immutable
public interface PathScope extends ExtensibleEnum {

    // TODO: what if I simply want all dependencies ?
    @Nonnull
    ProjectScope projectScope();

    @Nonnull
    Set<DependencyScope> dependencyScopes();

    PathScope MAIN_COMPILE = pathScope(
            "main-compile",

				return
			}
			di, err := disks[i].DiskInfo(context.Background(), DiskInfoOptions{})
			if err != nil || di.Healing {
				// - Do not consume disks which are not reachable
				//   unformatted or simply not accessible for some reason.
				//
				// - Do not consume disks which are being healed
				//
				// - Future: skip busy disks
				return
			}

			mu.Lock()
			newDisks = append(newDisks, disks[i])

{* ../../docs_src/dependencies/tutorial011_an_py39.py hl[22] *}

/// tip | Consejo

Todo esto podría parecer complicado. Y puede que no esté muy claro cómo es útil aún.

Estos ejemplos son intencionalmente simples, pero muestran cómo funciona todo.

En los capítulos sobre seguridad, hay funciones utilitarias que se implementan de esta misma manera.