// Create new Mac instance for thread safety without blocking other operations
            Mac mac;
            try {
                mac = createMacInstance();
            } catch (GeneralSecurityException e) {
                log.error("Failed to create Mac instance for signing", e);
                throw new RuntimeException("Failed to create Mac instance", e);
            }

## Crear un modelo de usuario { #create-a-user-model }

Primero, vamos a crear un modelo de usuario con Pydantic.

De la misma manera que usamos Pydantic para declarar cuerpos, podemos usarlo en cualquier otra parte:

{* ../../docs_src/security/tutorial002_an_py310.py hl[5,12:6] *}

## Crear una dependencia `get_current_user` { #create-a-get-current-user-dependency }

        assertNotNull(properties, "properties element should be created");
        assertNotNull(dependencies, "dependencies element should be created");

        String xmlOutput = DomUtils.toXml(doc);

        // Verify elements are created and positioned correctly
        int versionIndex = xmlOutput.indexOf("<version>1.0.0</version>");

h4. Generation of plugin metadata and packaging

To create the packaging for a plugin a special Maven packaging would be created with an accompanying life-cycle in order to create the plugin metadata required and create an archive of the plugin that can be consumed at runtime.

h3. Creation of an isolated classloader

   * lifetime of the cache.
   *
   * <p><b>Warning:</b> this cache may not be recording statistical data. For example, a cache
   * created using {@link CacheBuilder} only does so if the {@link CacheBuilder#recordStats} method
   * was called. If statistics are not being recorded, a {@code CacheStats} instance with zero for
   * all values is returned.
   *
   */

### Crear una clase personalizada `GzipRequest` { #create-a-custom-gziprequest-class }

/// tip | Consejo

Este es un ejemplo sencillo para demostrar cómo funciona. Si necesitas soporte para Gzip, puedes usar el [`GzipMiddleware`](../advanced/middleware.md#gzipmiddleware){.internal-link target=_blank} proporcionado.

///

But it's the simplest way to focus on the server-side of WebSockets and have a working example:

{* ../../docs_src/websockets/tutorial001_py39.py hl[2,6:38,41:43] *}

## Create a `websocket` { #create-a-websocket }

In your **FastAPI** application, create a `websocket`:

{* ../../docs_src/websockets/tutorial001_py39.py hl[1,46:47] *}

/// note | Technical Details

You could also use `from starlette.websockets import WebSocket`.

    @Mock
    private TransactNamedPipeInputStream mockPipeIn;

    @InjectMocks
    private TransTransactNamedPipeResponse response;

    @BeforeEach
    void setUp() {
        // Initialize mocks created above
        MockitoAnnotations.openMocks(this);
        // We need to manually inject the mock as we are not using @InjectMocks on the constructor
        response = new TransTransactNamedPipeResponse(mockPipe);
    }

    //                                                                              Create
    //                                                                              ======
    public SMailDeliveryDepartment create() {
        return new SMailDeliveryDepartment(createPostalParkingLot(), createPostalPersonnel());
    }

                  @Override
                  @SuppressWarnings({"unchecked", "rawtypes"})
                  public Map<Class, Impl> create(Object... elements) {
                    MutableClassToInstanceMap<Impl> map = MutableClassToInstanceMap.create();
                    for (Object object : elements) {
                      Entry<Class, Impl> entry = (Entry<Class, Impl>) object;