```Python hl_lines="9-13  36-53"
{!../../docs_src/openapi_callbacks/tutorial001.py!}
```

/// tip | Dica

O parâmetro de consulta `callback_url` usa um tipo Pydantic <a href="https://docs.pydantic.dev/latest/api/networks/" class="external-link" target="_blank">Url</a>.

///

A única coisa nova é o argumento `callbacks=invoices_callback_router.routes` no decorador da *operação de rota*. Veremos o que é isso a seguir.

    /**
     * Indicates whether network access to remote repositories has been disabled.
     *
     * @return {@code true} if remote access has been disabled, {@code false} otherwise.
     */
    boolean isOffline();

    /**
     * Enables/disables network access to remote repositories.
     *
     * @param offline {@code true} to disable remote access, {@code false} to allow network access.

    /**
     * Indicates whether network access to remote repositories has been disabled.
     *
     * @return {@code true} if remote access has been disabled, {@code false} otherwise.
     */
    boolean isOffline();

    /**
     * Enables/disables network access to remote repositories.
     *
     * @param offline {@code true} to disable remote access, {@code false} to allow network access.

- Kube-proxy uses  field-selector clusterIP!=None on Services to avoid watching for Headless Services, reduce  unnecessary network bandwidth ([#126769](https://github.com/kubernetes/kubernetes/pull/126769), [@Sakuralbj](https://github.com/Sakuralbj)) [SIG Network]

# Custom Docs UI Static Assets (Self-Hosting)

The API docs use **Swagger UI** and **ReDoc**, and each of those need some JavaScript and CSS files.

By default, those files are served from a <abbr title="Content Delivery Network: A service, normally composed of several servers, that provides static files, like JavaScript and CSS. It's commonly used to serve those files from the server closer to the client, improving performance.">CDN</abbr>.

   | This is a list of proxies which can be used on this machine to connect to the network.
   | Unless otherwise specified (by system property or command-line switch), the first proxy
   | specification in this list marked as active will be used.
   |-->
  <proxies>
    <!-- proxy
     | Specification for one proxy, to be used in connecting to the network.
     |
    <proxy>
      <id>optional</id>
      <active>true</active>

   policy enforcement and telemetry recording/reporting
   functions.

  > Note: The service mesh is not an overlay network. It
  > simplifies and enhances how microservices in an application talk to each
  > other over the network provided by the underlying platform.

      <configuration>
        <![CDATA[
    <offline>true</offline>
    ]]></configuration>
      <description>
        <![CDATA[
      Flags the system as offline, to prevent accessing the network to resolve artifacts or execute plugins.

      NOTE: It's also possible to switch to offline mode on a per-build basis, using the '-o' command-line option.
    ]]></description>
    </expression>
    <expression>

/// tip

To know more about each status code and which code is for what, check the <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Status" class="external-link" target="_blank"><abbr title="Mozilla Developer Network">MDN</abbr> documentation about HTTP status codes</a>.

///

## Shortcut to remember the names

Let's see the previous example again:

{* ../../docs_src/response_status_code/tutorial001.py hl[6] *}

    }

    throw unknownHostException
  }

  private fun getCacheOnlyResponse(request: Request): Response? {
    if (client.cache != null) {
      try {
        // Use the cache without hitting the network first
        // 504 code indicates that the Cache is stale
        val onlyIfCached =
          CacheControl.Builder()
            .onlyIfCached()
            .build()

        var cacheUrl = request.url