* <code>java.io.File</code> usage; a '/' at the beginning of the second
 * parameter will still use the server component of the first parameter. The
 * examples below illustrate the resulting URLs when this second contructor
 * argument is used.
 *
 * <table border="1">
 * <caption>Examples Of SMB URLs When Augmented With A Second Constructor Parameter</caption>
 * <tr>
 * <td colspan="3">

## Usando `BackgroundTasks`

Primeiro, importe `BackgroundTasks` e defina um parâmetro em sua _função de operação de caminho_ com uma declaração de tipo de `BackgroundTasks`:

{* ../../docs_src/background_tasks/tutorial001.py hl[1,13] *}

O **FastAPI** criará o objeto do tipo `BackgroundTasks` para você e o passará como esse parâmetro.

## Criar uma função de tarefa

Crie uma função a ser executada como tarefa em segundo plano.

When defining WebSockets, you normally declare a parameter of type `WebSocket` and with it you can read data from the client and send data to it.

It is provided directly by Starlette, but you can import it from `fastapi`:

```python
from fastapi import WebSocket
```

/// tip

        CronExpression.class.isAnnotation();
        assertTrue(CronExpression.class.isAnnotation());

        // Check that annotation can be applied to METHOD, FIELD, ANNOTATION_TYPE, CONSTRUCTOR, PARAMETER
        java.lang.annotation.Target target = CronExpression.class.getAnnotation(java.lang.annotation.Target.class);
        assertNotNull(target);

        java.lang.annotation.ElementType[] types = target.value();

            digest.sign(dst, headerStart, length, this, response);
        }

        return length;
    }

    /*
     * We overload this because we want readAndXWireFormat to
     * read the parameter words and bytes. This is so when
     * commands are batched together we can recursivly call
     * readAndXWireFormat without reading the non-existent header.
     */

    @Override

          // TODO(cgdecker): Should check for a generic parameter type and error out
          Class<?>[] parameterTypes = method.getParameterTypes();
          checkArgument(
              parameterTypes.length == 1,
              "Method %s has @Subscribe annotation but has %s parameters. "
                  + "Subscriber methods must have exactly 1 parameter.",
              method,
              parameterTypes.length);

As an example, let's take this function:

{* ../../docs_src/python_types/tutorial009c.py hl[1,4] *}

The parameter `name` is defined as `Optional[str]`, but it is **not optional**, you cannot call the function without the parameter:

```Python
say_hi()  # Oh, no, this throws an error! 😱
```

The `name` parameter is **still required** (not *optional*) because it doesn't have a default value. Still, `name` accepts `None` as the value:

import org.codelibs.fess.Constants;
import org.dbflute.optional.OptionalThing;

/**
 * Utility class for managing field configurations with parameter mappings.
 * This class provides functionality to retrieve and manage field-specific configurations
 * from a parameter map.
 */
public class FieldConfigs {

    /**
     * Map containing field names as keys and their corresponding configuration values as values.
     */

Betrachten wir die deklarierten Parameter:

* Obwohl diese Funktion selbst eine Abhängigkeit ist („Dependable“, etwas hängt von ihr ab), deklariert sie auch eine andere Abhängigkeit („Dependant“, sie hängt von etwas anderem ab).
    * Sie hängt von `query_extractor` ab und weist den von diesem zurückgegebenen Wert dem Parameter `q` zu.
* Sie deklariert außerdem ein optionales `last_query`-Cookie, ein `str`.

        // The method should write parameter words
        assertTrue(result >= 0, "writeParameterWordsWireFormat should return non-negative value");
    }

    @Test
    void testReadParameterWordsWireFormat() {
        byte[] buffer = new byte[1024];
        int result = response.readParameterWordsWireFormat(buffer, 0);

        // The method should read parameter words