// https://docs.aws.amazon.com/AmazonS3/latest/API/API_HeadObject.html#API_HeadObject_ResponseSyntax
		w.Header()[xhttp.AmzStorageClass] = []string{filterStorageClass(ctx, objInfo.TransitionedObject.Tier)}
	}

	if lc, err := globalLifecycleSys.Get(objInfo.Bucket); err == nil {
		lc.SetPredictionHeaders(w, objInfo.ToLifecycleOpts())
	}

	if v, ok := objInfo.UserDefined[ReservedMetadataPrefix+"compression"]; ok {

But by default, it all **"just works"**.

### Validation { #validation }

* Validation for most (or all?) Python **data types**, including:
    * JSON objects (`dict`).
    * JSON array (`list`) defining item types.
    * String (`str`) fields, defining min and max lengths.
    * Numbers (`int`, `float`) with min and max values, etc.

* Validation for more exotic types, like:
    * URL.
    * Email.
    * UUID.

Hepsi varsayılan olarak **çalışıyor**.


### Doğrulama

* Neredeyse bütün (ya da hepsi?) Python **data typeları** için doğrulama, kapsadıkları:
    * JSON objeleri (`dict`).
    * JSON array (`list`) item type'ı belirtirken.
    * String (`str`) parametresi, minimum ve maksimum uzunluk gibi sınırlandırmalar yaparken.
    * Numaralar (`int`, `float`) maksimum ve minimum gibi sınırlandırmalar yaparken.

		Help:      "Total bytes transitioned to a tier",
		Type:      gaugeMetric,
	}
}

func getClusterTransitionedObjectsMD() MetricDescription {
	return MetricDescription{
		Namespace: clusterMetricNamespace,
		Subsystem: ilmSubsystem,
		Name:      transitionedObjects,
		Help:      "Total number of objects transitioned to a tier",
		Type:      gaugeMetric,
	}
}

		p.lineNum = p.lex.Line()
		switch tok {
		case '\n', ';':
			continue
		case scanner.EOF:
			return "", "", nil, false
		}
		break
	}
	// First item must be an identifier.
	if tok != scanner.Ident {
		p.errorf("expected identifier, found %q", p.lex.Text())
		return "", "", nil, false // Might as well stop now.
	}
	word, cond = p.lex.Text(), ""

///

## Escopos OAuth2 e OpenAPI { #oauth2-scopes-and-openapi }

A especificação OAuth2 define "escopos" como uma lista de strings separadas por espaços.

O conteúdo de cada uma dessas strings pode ter qualquer formato, mas não devem possuir espaços.

Estes escopos representam "permissões".

No OpenAPI (e.g. os documentos da API), você pode definir "esquemas de segurança".

クライアントが`http://example.com/items/foo`（`item_id` `"foo"`）をリクエストすると、HTTPステータスコードが200で、以下のJSONレスポンスが返されます:

```JSON
{
  "item": "The Foo Wrestlers"
}
```

しかし、クライアントが`http://example.com/items/bar`（存在しない`item_id` `"bar"`）をリクエストした場合、HTTPステータスコード404（"not found"エラー）と以下のJSONレスポンスが返されます:

```JSON
{
  "detail": "Item not found"
}
```

/// tip | 豆知識

`HTTPException`を発生させる際には、`str`だけでなく、JSONに変換できる任意の値を`detail`パラメータとして渡すことができます。

		if nErr.Err != nil {
			peersLogOnceIf(logger.SetReqInfo(ctx, reqInfo), nErr.Err, nErr.Host.String())
		}
	}
}

// LoadTransitionTierConfig notifies remote peers to load their remote tier
// configs from config store.
func (sys *NotificationSys) LoadTransitionTierConfig(ctx context.Context) {
	ng := WithNPeers(len(sys.peerClients))
	for idx, client := range sys.peerClients {
		if client == nil {

这表示："变量 `items` 是一个 `list`，并且这个列表里的每一个元素都是 `str`"。

这样，即使在处理列表中的元素时，你的编辑器也可以提供支持。

没有类型，几乎是不可能实现下面这样：

<img src="https://fastapi.tiangolo.com/img/python-types/image05.png">

注意，变量 `item` 是列表 `items` 中的元素之一。

而且，编辑器仍然知道它是一个 `str`，并为此提供了支持。

#### 元组和集合

声明 `tuple` 和 `set` 的方法也是一样的：

{* ../../docs_src/python_types/tutorial007.py hl[1,4] *}


这表示：

	// The usual case is caught by Push, below, but be safe.
	for nesting := 0; nesting < 100; {
		tok := in.Stack.Next()
		switch tok {
		case '#':
			if !in.beginningOfLine {
				in.Error("'#' must be first item on line")
			}
			in.beginningOfLine = in.hash()
			in.text = "#"
			return '#'

		case scanner.Ident:
			// Is it a macro name?
			name := in.Stack.Text()
			macro := in.macros[name]