그리고 이를 어트리뷰트의 타입으로 사용할 수 있습니다:

{* ../../docs_src/body_nested_models/tutorial004_py310.py hl[18] *}

이는 **FastAPI**가 다음과 유사한 본문을 기대한다는 것을 의미합니다:

```JSON
{
    "name": "Foo",
    "description": "The pretender",
    "price": 42.0,
    "tax": 3.2,
    "tags": ["rock", "metal", "bar"],
    "image": {
        "url": "http://example.com/baz.jpg",
        "name": "The Foo live"
    }
}
```

## 文件化回呼 { #documenting-the-callback }

實際的回呼程式碼會高度依賴你的 API 應用本身。

而且很可能每個應用都差很多。

它可能就只有一兩行，例如：

```Python
callback_url = "https://example.com/api/v1/invoices/events/"
httpx.post(callback_url, json={"description": "Invoice paid", "paid": True})
```

但回呼中最重要的部分，可能是在確保你的 API 使用者（外部開發者）能正確實作「外部 API」，符合「你的 API」在回呼請求 body 中要送出的資料格式，等等。

因此，接下來我們要加上用來「文件化」說明，該「外部 API」應該長什麼樣子，才能接收來自「你的 API」的回呼。

### 將子模型作為型別使用 { #use-the-submodel-as-a-type }

然後把它作為某個屬性的型別使用：

{* ../../docs_src/body_nested_models/tutorial004_py310.py hl[18] *}

這表示 **FastAPI** 會期望一個類似如下的本文：

```JSON
{
    "name": "Foo",
    "description": "The pretender",
    "price": 42.0,
    "tax": 3.2,
    "tags": ["rock", "metal", "bar"],
    "image": {
        "url": "http://example.com/baz.jpg",
        "name": "The Foo live"
    }
}
```

{* ../../docs_src/body_nested_models/tutorial004_py310.py hl[18] *}

This would mean that **FastAPI** would expect a body similar to:

```JSON
{
    "name": "Foo",
    "description": "The pretender",
    "price": 42.0,
    "tax": 3.2,
    "tags": ["rock", "metal", "bar"],
    "image": {
        "url": "http://example.com/baz.jpg",
        "name": "The Foo live"
    }
}
```

     * Maximum length is 20 characters.
     */
    @Required
    @Size(max = 20)
    public String sessionId;

    /**
     * The name or description of the crawling session.
     * This is an optional descriptive field with a maximum length of 20 characters.
     */
    @Size(max = 20)
    public String name;

    /**
     * The expiration time for the crawling session.

        @DisplayName("should reject invalid version formats")
        void shouldRejectInvalidVersionFormats(String version, String description) {
            assertFalse(
                    ModelVersionUtils.isValidModelVersion(version), "Should reject " + description + ": " + version);
        }

        private static Stream<Arguments> provideInvalidVersions() {
            return Stream.of(

    @get:Optional
    @get:Option(option = "fix", description = "When enabled, will write the correct computed runtimes back to the build files")
    abstract val fix: Property<Boolean>

    /**
     * If enabled, prints extra details describing why a target runtime declaration is invalid.
     */
    @get:Input
    @get:Optional

	if targetUser == "" {
		targetUser = cred.AccessKey
	}

	description := createReq.Description
	if description == "" {
		description = createReq.Comment
	}
	opts := newServiceAccountOpts{
		accessKey:   createReq.AccessKey,
		secretKey:   createReq.SecretKey,
		name:        createReq.Name,
		description: description,
		expiration:  createReq.Expiration,
		claims:      make(map[string]any),
	}

            "departmentNumber", null, false, false, false, "keyword", 0, 0, null, null, false, null, null, null, null, null, false);
    protected final ColumnInfo _columnDescription = cci("description", "description", null, null, String.class, "description", null, false,
            false, false, "keyword", 0, 0, null, null, false, null, null, null, null, null, false);

    }

    public interface ContentTransformer {
        /**
         * Interpolate the value read from the xpp3 document
         *
         * @param source    the source value
         * @param fieldName a description of the field being interpolated. The implementation may use this to
         *                  log stuff
         * @return the interpolated value
         */
        String transform(String source, String fieldName);