* Validate that there is an `item_id` in the path for `GET` and `PUT` requests.
* Validate that the `item_id` is of type `int` for `GET` and `PUT` requests.
    * If it is not, the client will see a useful, clear error.
* Check if there is an optional query parameter named `q` (as in `http://127.0.0.1:8000/items/foo?q=somequery`) for `GET` requests.
    * As the `q` parameter is declared with `= None`, it is optional.

   * immediately unless there are several other requests currently being executed.
   *
   * This client will later call back `responseCallback` with either an HTTP response or a failure
   * exception.
   *
   * @throws IllegalStateException when the call has already been executed.
   */
  fun enqueue(responseCallback: Callback)

  /** Cancels the request, if possible. Requests that are already complete cannot be canceled. */

 * Fix: Change HTTP date formats to UTC to conform to RFC2616 section 3.3.
 * Fix: Support SPDY header blocks with trailing bytes.
 * Fix: Allow `;` as separator for `Cache-Control` header.
 * Fix: Correct bug where HTTPS POST requests were always automatically buffered.
 * Fix: Honor read timeout when parsing SPDY headers.


## Version 1.2.1

_2013-08-23_

 * Resolve issue with 'jar-with-dependencies' artifact creation.

* `max_age` - 设定浏览器缓存 CORS 响应的最长时间，单位是秒。默认为 `600`。

中间件响应两种特定类型的 HTTP 请求...

### CORS 预检请求 { #cors-preflight-requests }

这是些带有 `Origin` 和 `Access-Control-Request-Method` 请求头的 `OPTIONS` 请求。

在这种情况下，中间件将拦截传入的请求并进行响应，出于提供信息的目的返回一个使用了适当的 CORS headers 的 `200` 或 `400` 响应。

### 简单请求 { #simple-requests }

任何带有 `Origin` 请求头的请求。在这种情况下，中间件将像平常一样传递请求，但是在响应中包含适当的 CORS headers。

## 更多信息 { #more-info }

    @Required
    @Min(value = 1)
    @Max(value = 2147483647)
    @ValidateTypeFailure
    public Integer numOfThread;

    /** The interval time between crawl requests in milliseconds (required, 0 to 2147483647). */
    @Required
    @Min(value = 0)
    @Max(value = 2147483647)
    @ValidateTypeFailure
    public Integer intervalTime;

# Usando Dataclasses { #using-dataclasses }

FastAPI está construido sobre **Pydantic**, y te he estado mostrando cómo usar modelos de Pydantic para declarar requests y responses.

Pero FastAPI también soporta el uso de [`dataclasses`](https://docs.python.org/3/library/dataclasses.html) de la misma manera:

{* ../../docs_src/dataclasses_/tutorial001_py310.py hl[1,6:11,18:19] *}

        }
    }

    @Nested
    @DisplayName("Chain Operation Tests")
    class ChainOperationTests {

        @Test
        @DisplayName("allowChain should check configuration for both requests")
        void testAllowChain() {
            TestServerMessageBlock2Request nextRequest = new TestServerMessageBlock2Request(mockConfig);

/// tip | Consejo

El callback real es solo un request HTTP.

Cuando implementes el callback tú mismo, podrías usar algo como [HTTPX](https://www.python-httpx.org) o [Requests](https://requests.readthedocs.io/).

///

## Escribe el código de documentación del callback { #write-the-callback-documentation-code }

 *
 *  * **[Request Count:][requestCount]** the number of HTTP requests issued since this cache was
 *    created.
 *  * **[Network Count:][networkCount]** the number of those requests that required network use.
 *  * **[Hit Count:][hitCount]** the number of those requests whose responses were served by the
 *    cache.
 *

		return nil, ErrDisconnected
	}
	handler := c.handlers.streams[h]
	if handler == nil {
		return nil, ErrUnknownHandler
	}

	var requests chan []byte
	var responses chan Response
	if handler.InCapacity > 0 {
		requests = make(chan []byte, handler.InCapacity)
	}
	if handler.OutCapacity > 0 {
		responses = make(chan Response, handler.OutCapacity)
	} else {