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

        </executions>
      </plugin>
      <plugin>
        <groupId>com.github.siom79.japicmp</groupId>
        <artifactId>japicmp-maven-plugin</artifactId>
        <configuration>
          <parameter>
            <includes>
              <include>org.apache.maven.toolchain.model</include>
            </includes>
            <excludes>

            data = websocket.receive_text()
            assert data == "Session cookie or query token value is: some-token"
            data = websocket.receive_text()
            assert data == "Query parameter q is: 3"
            data = websocket.receive_text()
            assert data == f"Message text was: {message}, for item ID: 2"
            message = "Message two"
            websocket.send_text(message)

#
map:{
    # /- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
    # o isGenerateProcedureParameterBean: (NotRequired - Default false)
    #   [true]
    #     The parameter beans for procedure are auto-generated.
    #     If you call the procedure from DBFlute, you should specify 'true'!
    #
    ; isGenerateProcedureParameterBean = false
    # - - - - - - - - - -/

The `lifespan` parameter of the `FastAPI` app takes an **async context manager**, so we can pass our new `lifespan` async context manager to it.

{* ../../docs_src/events/tutorial003.py hl[22] *}

## Alternative Events (deprecated)

/// warning

OpenAPI fügte auch die Felder `example` und `examples` zu anderen Teilen der Spezifikation hinzu:

* <a href="https://github.com/OAI/OpenAPI-Specification/blob/main/versions/3.1.0.md#parameter-object" class="external-link" target="_blank">`Parameter Object` (in der Spezifikation)</a>, das verwendet wurde von FastAPIs:
    * `Path()`
    * `Query()`
    * `Header()`
    * `Cookie()`

/**
 * An interface for representing and manipulating an origin node's adjacent nodes and edge values in
 * a {@link Graph}.
 *
 * @author James Sexton
 * @param <N> Node parameter type
 * @param <V> Value parameter type
 */
@ElementTypesAreNonnullByDefault
interface GraphConnections<N, V> {

  Set<N> adjacentNodes();

  Set<N> predecessors();

  Set<N> successors();

  /**

import java.util.Set;
import javax.annotation.CheckForNull;

/**
 * A base implementation of {@link NetworkConnections} for undirected networks.
 *
 * @author James Sexton
 * @param <N> Node parameter type
 * @param <E> Edge parameter type
 */
@ElementTypesAreNonnullByDefault
abstract class AbstractUndirectedNetworkConnections<N, E> implements NetworkConnections<N, E> {

            data = websocket.receive_text()
            assert data == "Session cookie or query token value is: some-token"
            data = websocket.receive_text()
            assert data == "Query parameter q is: 3"
            data = websocket.receive_text()
            assert data == f"Message text was: {message}, for item ID: 2"
            message = "Message two"
            websocket.send_text(message)

## Usando `BackgroundTasks`

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

```Python hl_lines="1  13"
{!../../docs_src/background_tasks/tutorial001.py!}
```

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

## Criar uma função de tarefa