var idxCb func() []byte
	if isCompressed {
		wantEncryption := crypto.Requested(r.Header) || isEncrypted
		s2c, cb := newS2CompressReader(reader, actualPartSize, wantEncryption)
		idxCb = cb
		defer s2c.Close()
		reader = etag.Wrap(s2c, reader)
		length = -1
	}

	srcInfo.Reader, err = hash.NewReader(ctx, reader, length, "", "", actualPartSize)
	if err != nil {

		compressMetadata[ReservedMetadataPrefix+"actual-size"] = strconv.FormatInt(actualSize, 10)

		reader = etag.NewReader(ctx, reader, nil, nil)
		wantEncryption := crypto.Requested(r.Header)
		s2c, cb := newS2CompressReader(reader, actualSize, wantEncryption)
		dstOpts.IndexCB = cb
		defer s2c.Close()
		reader = etag.Wrap(s2c, reader)
		length = -1
	} else {
		delete(srcInfo.UserDefined, ReservedMetadataPrefix+"compression")

}

// Apply applies the SSE bucket configuration on the given HTTP headers and
// sets the specified SSE headers.
//
// Apply does not overwrite any existing SSE headers. Further, it will
// set minimal SSE-KMS headers if autoEncrypt is true and the BucketSSEConfig
// is nil.
func (b *BucketSSEConfig) Apply(headers http.Header, opts ApplyOptions) {
	if crypto.Requested(headers) {
		return
	}
	if b == nil {
		if opts.AutoEncrypt {

            data: Union[str, None] = Header(
                default=None,
                example="header1",
            ),
        ):
            return data

    @app.get("/header_examples/")
    def header_examples(
        data: Union[str, None] = Header(
            default=None,
            examples=[
                "header1",
                "header2",
            ],
        ),
    ):

render-banner.svg...

# Header 参数

定义 `Header` 参数的方式与定义 `Query`、`Path`、`Cookie` 参数相同。

## 导入 `Header`

首先，导入 `Header`：

{* ../../docs_src/header_params/tutorial001_an_py310.py hl[3] *}

## 声明 `Header` 参数

然后，使用和 `Path`、`Query`、`Cookie` 一样的结构定义 header 参数。

第一个值是默认值，还可以传递所有验证参数或注释参数：

{* ../../docs_src/header_params/tutorial001_an_py310.py hl[9] *}

/// note | 技术细节

`Header` 是 `Path`、`Query`、`Cookie` 的**兄弟类**，都继承自共用的 `Param` 类。

			fmt.Println(args...)
		}
	}
	// Inject random reader/writer sleeps.
	const maxSleep = int(1 * time.Millisecond)
	doSleep := !testing.Short()
	rb := New(4 << 10).SetBlocking(true)

	// Reader
	var readErr error
	var wg sync.WaitGroup
	wg.Add(1)
	go func() {
		readRng := rand.New(rand.NewSource(1))
		defer wg.Done()
		defer rb.CloseWithError(readErr)
		buf := make([]byte, 1024)
		for {
			// Read

## `Header` 임포트

먼저 `Header`를 임포트합니다:

{* ../../docs_src/header_params/tutorial001.py hl[3] *}

## `Header` 매개변수 선언

`Path`, `Query` 그리고 `Cookie`를 사용한 동일한 구조를 이용하여 헤더 매개변수를 선언합니다.

첫 번째 값은 기본값이며, 추가 검증이나 어노테이션 매개변수 모두 전달할 수 있습니다:

{* ../../docs_src/header_params/tutorial001.py hl[9] *}

/// note | 기술 세부사항

	UserTags string

	// List of individual parts, maximum size of upto 10,000
	Parts []ObjectPartInfo `json:"-"`

	// Implements writer and reader used by CopyObject API
	Writer       io.WriteCloser `json:"-" msg:"-"`
	Reader       *hash.Reader   `json:"-" msg:"-"`
	PutObjReader *PutObjReader  `json:"-" msg:"-"`

	metadataOnly bool
	versionOnly  bool // adds a new version, only used by CopyObject

		return map[string]string{}
	}
	return map[string]string{
		"requestId":      w.Header().Get(xhttp.AmzRequestID),
		"nodeId":         w.Header().Get(xhttp.AmzRequestHostID),
		"content-length": w.Header().Get(xhttp.ContentLength),
		// Add more fields here.
	}
}

// Trims away `aws-chunked` from the content-encoding header if present.
// Streaming signature clients can have custom content-encoding such as