## Pydantic 모델을 사용한 헤더 매개변수

**Pydantic 모델**에 필요한 **헤더 매개변수**를 선언한 다음, 해당 매개변수를 `Header`로 선언합니다:

{* ../../docs_src/header_param_models/tutorial001_an_py310.py hl[9:14,18] *}

**FastAPI**는 요청에서 받은 **헤더**에서 **각 필드**에 대한 데이터를 **추출**하고 정의한 Pydantic 모델을 줍니다.

## 문서 확인하기

문서 UI `/docs`에서 필요한 헤더를 볼 수 있습니다:

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

## 추가 헤더 금지하기

 */
class Http2Reader(
  /** Creates a frame reader with max header table size of 4096. */
  private val source: BufferedSource,
  private val client: Boolean,
) : Closeable {
  private val continuation: ContinuationSource = ContinuationSource(this.source)
  private val hpackReader: Hpack.Reader =
    Hpack.Reader(
      source = continuation,
      headerTableSizeSetting = 4096,
    )

      Header("content-disposition", ""),
      Header("content-encoding", ""),
      Header("content-language", ""),
      Header("content-length", ""),
      Header("content-location", ""),
      Header("content-range", ""),
      Header("content-type", ""),
      Header("cookie", ""),
      Header("date", ""),
      Header("etag", ""),
      Header("expect", ""),
      Header("expires", ""),

# Модели Header-параметров

Если у вас есть группа связанных **header-параметров**, то вы можете объединить их в одну **Pydantic-модель**.

Это позволит вам **переиспользовать модель** в **разных местах**, а также задать валидацию и метаданные сразу для всех параметров. 😎

/// note | Заметка

Этот функционал доступен в FastAPI начиная с версии `0.115.0`. 🤓

///

## Header-параметры в виде Pydantic-модели

    }

    /**
     * Checks if `expected` and `observed` are equal when viewed as a set and headers are
     * deduped.
     *
     * TODO: See if duped headers should be preserved on decode and verify.
     */
    private fun assertSetEquals(
      message: String,
      expected: List<Header>,
      observed: List<Header>,
    ) {
      assertThat(LinkedHashSet(observed), message)
        .isEqualTo(LinkedHashSet(expected))

      }
      dataStream.receiveData(source, length)
      if (inFinished) {
        dataStream.receiveHeaders(Headers.EMPTY, true)
      }
    }

    override fun headers(
      inFinished: Boolean,
      streamId: Int,
      associatedStreamId: Int,
      headerBlock: List<Header>,
    ) {
      if (pushedStream(streamId)) {
        pushHeadersLater(streamId, headerBlock, inFinished)
        return

        .protocols(ONLY_HTTP1)
        .build()
    val request =
      originalRequest
        .newBuilder()
        .header("Upgrade", "websocket")
        .header("Connection", "Upgrade")
        .header("Sec-WebSocket-Key", key)
        .header("Sec-WebSocket-Version", "13")
        .header("Sec-WebSocket-Extensions", "permessage-deflate")
        .build()
    call = RealCall(webSocketClient, request, forWebSocket = true)

Koki Igarashi <******@****.***> 1581071331 +0900

  public val settings: Settings

  public constructor(
    code: Int = 200,
    headers: Headers = headersOf(),
    body: String = "",
  ) : this(
    Builder()
      .code(code)
      .headers(headers)
      .body(body),
  )

  private constructor(builder: Builder) {
    this.status = builder.status
    this.headers = builder.headers
    this.trailers = builder.trailers
    this.body = builder.body

    val derReader = DerReader(buffer)

    derReader.read("test") { header ->
      assertThat(header.tag).isEqualTo(7L)
      assertThat(header.tagClass).isEqualTo(DerHeader.TAG_CLASS_APPLICATION)
      assertThat(header.length).isEqualTo(7L)

      derReader.read("test") { header2 ->
        assertThat(header2.tag).isEqualTo(3L)
        assertThat(header2.tagClass).isEqualTo(DerHeader.TAG_CLASS_APPLICATION)