override fun requestHeadersEnd(
    call: Call,
    request: Request,
  ) = logEvent(RequestHeadersEnd(System.nanoTime(), call, request.headers.byteCount()))

  override fun requestBodyStart(call: Call) = logEvent(RequestBodyStart(System.nanoTime(), call))

  override fun requestBodyEnd(
    call: Call,
    byteCount: Long,

O **FastAPI** irá **extrair** os dados de **cada campo** a partir dos **cabeçalhos** da requisição e te retornará o modelo do Pydantic que você definiu.

### Checando a documentação

Você pode ver os headers necessários na interface gráfica da documentação em `/docs`:

<div class="screenshot">
<img src="/img/tutorial/header-param-models/image01.png">
</div>

### Proibindo Cabeçalhos adicionais

import okio.Buffer
import org.junit.jupiter.api.Assumptions.assumeFalse
import org.junit.jupiter.params.ParameterizedTest
import org.junit.jupiter.params.provider.ArgumentsSource

/**
 * Tests for round-tripping headers through hpack.
 *
 * TODO: update hpack-test-case with the output of our encoder.
 * This test will hide complementary bugs in the encoder and decoder,
 * We should test that the encoder is producing responses that are
 */

* 👆 💪 ⤴️ 🔀 🌅 `response` ⏭ 🛬 ⚫️.

{* ../../docs_src/middleware/tutorial001.py hl[8:9,11,14] *}

/// tip

✔️ 🤯 👈 🛃 © 🎚 💪 🚮 <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers" class="external-link" target="_blank">⚙️ '✖-' 🔡</a>.

  }

  @Test
  fun worksIfTrailersSet() {
    val response =
      newResponse("".toResponseBody()) {
        trailers(
          object : TrailersSource {
            override fun get() = Headers.headersOf("a", "b")
          },
        )
      }

    assertThat(response.trailers()["a"]).isEqualTo("b")
  }

  @Test fun peekAfterReadingResponse() {
    val response = newResponse(responseBody("abc"))

    assertThat(cacheControl.onlyIfCached).isTrue()
    assertThat(cacheControl.noTransform).isTrue()
    assertThat(cacheControl.immutable).isTrue()

    // These members are accessible to response headers only.
    assertThat(cacheControl.sMaxAgeSeconds).isEqualTo(-1)
    assertThat(cacheControl.isPrivate).isFalse()
    assertThat(cacheControl.isPublic).isFalse()
    assertThat(cacheControl.mustRevalidate).isFalse()
  }

* Para pasar un cuerpo JSON, pasa un objeto de Python (por ejemplo, un `dict`) al parámetro `json`.
* Si necesitas enviar *Form Data* en lugar de JSON, usa el parámetro `data` en su lugar.
* Para pasar *headers*, usa un `dict` en el parámetro `headers`.
* Para *cookies*, un `dict` en el parámetro `cookies`.

```python
from fastapi import UploadFile
```

::: fastapi.UploadFile
    options:
        members:
            - file
            - filename
            - size
            - headers
            - content_type
            - read
            - write
            - seek

    chain and an untrusted-but-pinned chain.
 *  Upgrade: [Kotlin 1.6.10][kotlin_1_6_10].


## Version 5.0.0-alpha.3

_2021-11-22_

 *  Fix: Change `Headers.toString()` to redact authorization and cookie headers.
 *  Fix: Don't do DNS to get the hostname for `RecordedRequest.requestUrl`. This was doing a DNS
    lookup for the local hostname, but we really just wanted the `Host` header.

Вы можете использовать **Pydantic-модели** для объявления **query-параметров** в **FastAPI**. 😎

/// tip | Совет

Спойлер: вы также можете использовать Pydantic-модели для группировки кук (cookies) и заголовков (headers), но об этом вы прочитаете позже. 🤫