"Access-Control-Request-Headers": "X-Example",
    }
    response = client.options("/", headers=headers)
    assert response.status_code == 200, response.text
    assert response.text == "OK"
    assert (
        response.headers["access-control-allow-origin"]
        == "https://localhost.tiangolo.com"
    )
    assert response.headers["access-control-allow-headers"] == "X-Example"

    # Test standard response

**FastAPI** provides a convenience tool to structure your application while keeping all the flexibility.

/// info

If you come from Flask, this would be the equivalent of Flask's Blueprints.

///

## An example file structure

Let's say you have a file structure like this:

```
.
├── app
│   ├── __init__.py
│   ├── main.py
│   ├── dependencies.py
│   └── routers
│   │   ├── __init__.py

  optional string type = 1;

  // object refers to a metric describing a single kubernetes object
  // (for example, hits-per-second on an Ingress object).
  // +optional
  optional ObjectMetricSource object = 2;

  // pods refers to a metric describing each pod in the current scale target
  // (for example, transactions-processed-per-second).  The values will be
  // averaged together before being compared to the target value.

  optional string type = 1;

  // object refers to a metric describing a single kubernetes object
  // (for example, hits-per-second on an Ingress object).
  // +optional
  optional ObjectMetricSource object = 2;

  // pods refers to a metric describing each pod in the current scale target
  // (for example, transactions-processed-per-second).  The values will be
  // averaged together before being compared to the target value.

Você também pode usar `.include_router()` várias vezes com o *mesmo* roteador usando prefixos diferentes.

Isso pode ser útil, por exemplo, para expor a mesma API sob prefixos diferentes, por exemplo, `/api/v1` e `/api/latest`.

Esse é um uso avançado que você pode não precisar, mas está lá caso precise.

## Incluir um `APIRouter` em outro

Isso inclui, por exemplo:

- Envio de notificações por email após a realização de uma ação:
  - Como conectar-se a um servidor de e-mail e enviar um e-mail tende a ser "lento" (vários segundos), você pode retornar a resposta imediatamente e enviar a notificação por e-mail em segundo plano.
- Processando dados:

This includes, for example:

* Email notifications sent after performing an action:
    * As connecting to an email server and sending an email tends to be "slow" (several seconds), you can return the response right away and send the email notification in the background.
* Processing data:

                </mxCell>
                <mxCell id="29" value="&lt;font face=&quot;Roboto&quot; data-font-src=&quot;https://fonts.googleapis.com/css?family=Roboto&quot; style=&quot;font-size: 24px&quot;&gt;https://someapp.example.com&lt;/font&gt;" style="rounded=0;whiteSpace=wrap;html=1;fontStyle=1;strokeWidth=4;" parent="33" vertex="1">
                    <mxGeometry x="60" y="27" width="380" height="250" as="geometry"/>
                </mxCell>

// that should not be included within this rule.
message IPBlock {
  // cidr is a string representing the IPBlock
  // Valid examples are "192.168.1.0/24" or "2001:db8::/64"
  optional string cidr = 1;

  // except is a slice of CIDRs that should not be included within an IPBlock
  // Valid examples are "192.168.1.0/24" or "2001:db8::/64"
  // Except values will be rejected if they are outside the cidr range
  // +optional

    open fun encode(codePoint: Int): String {
      throw UnsupportedOperationException()
    }
  }

  enum class Component {
    USER {
      override fun urlString(value: String): String = "http://$value@example.com/"

      override fun encodedValue(url: HttpUrl): String = url.encodedUsername

      override operator fun set(
        builder: HttpUrl.Builder,
        value: String,
      ) {