custom_encoder: Annotated[
        dict[Any, Callable[[Any], Any]] | None,
        Doc(
            """
            Pydantic's `custom_encoder` parameter, passed to Pydantic models to define
            a custom encoder.
            """
        ),
    ] = None,
    sqlalchemy_safe: Annotated[
        bool,
        Doc(
            """
            Exclude from the output any fields that start with the name `_sa`.

### 流式传输字节 { #stream-bytes }

主要的用例之一是流式传输 `bytes` 而不是字符串，这当然可以做到。

{* ../../docs_src/stream_data/tutorial001_py310.py ln[44:47] hl[47] *}

## 自定义 `PNGStreamingResponse` { #a-custom-pngstreamingresponse }

在上面的示例中，虽然按字节流式传输了数据，但响应没有 `Content-Type` 头，因此客户端不知道接收到的数据类型。

你可以创建 `StreamingResponse` 的自定义子类，将 `Content-Type` 头设置为你要流式传输的数据类型。

	ErrTokenExpired = errors.New("token expired")
)

func updateClaimsExpiry(dsecs string, claims map[string]any) error {
	expStr := claims["exp"]
	if expStr == "" {
		return ErrTokenExpired
	}

	// No custom duration requested, the claims can be used as is.
	if dsecs == "" {
		return nil
	}

	if _, err := auth.ExpToInt64(expStr); err != nil {
		return err
	}

     *
     * The server’s TLS certificate still must match the requested hostname. For example, if the
     * certificate is issued to `example.com` and the request is to `localhost`, the connection will
     * fail. Use a custom [HostnameVerifier] to ignore such problems.
     *
     * Other TLS features are still used but provide no security benefits in absence of the above

    }

    @Test
    public void test_getMessage() {
        // Test getMessage() method
        String message = "Custom SSO error message";
        SsoLoginException exception = new SsoLoginException(message);

        assertEquals(message, exception.getMessage());

        // Test with special characters

						References: []Reference{
							{ForeignKey: "OwnerType", ForeignSchema: "Toy", PrimaryValue: "users"},
						},
					},
				},
			},
		})
	})

	t.Run("has one with custom polymorphic type and id", func(t *testing.T) {
		type Toy struct {
			ID    int
			Name  string
			RefId int
			Type  string
		}

		type Cat struct {
			ID   int
			Name string

  /*
   * Under Android, MyError propagates up and fails the test?
   *
   * TODO(b/218700094): Does this matter to prod users, or is it just a feature of our testing
   * environment? If the latter, maybe write a custom Executor that avoids failing the test when it
   * sees an Error?
   */
  @AndroidIncompatible
  public void testTaskThrowsError() throws Exception {
    class MyError extends Error {}

		# Get the original S3 object using the presigned URL
		r = requests.get(s3_url)
		original_object = r.content.decode('utf-8')

		# Transform all text in the original object to uppercase
		# You can replace it with your custom code based on your use case
		transformed_object = original_object.upper()

		# Write object back to S3 Object Lambda
		# response sends the transformed data
		# back to MinIO and then to the user

        inlineMimeTypeSet.add(mimeType);
    }

    /**
     * Gets the action hook for custom processing.
     *
     * @return the action hook
     */
    public ActionHook getActionHook() {
        return actionHook;
    }

    /**
     * Sets the action hook for custom processing.
     *
     * @param actionHook the action hook to set
     */

所有这些都会被合并并包含到你的 OpenAPI 中，并显示在 API 文档里：

<img src="/img/tutorial/additional-responses/image01.png">

## 组合预定义响应和自定义响应 { #combine-predefined-responses-and-custom-ones }

你可能希望有一些适用于许多*路径操作*的预定义响应，但同时又想把它们与每个*路径操作*所需的自定义响应组合在一起。

在这些情况下，你可以使用 Python 的“解包”`dict` 的技巧 `**dict_to_unpack`：

```Python
old_dict = {
    "old key": "old value",