///

Then we can create an `AsyncClient` with the app, and send async requests to it, using `await`.

{* ../../docs_src/async_tests/app_a_py39/test_main.py hl[9:12] *}

This is the equivalent to:

```Python
response = client.get('/')
```

...that we used to make our requests with the `TestClient`.

/// tip

Note that we're using async/await with the new `AsyncClient` - the request is asynchronous.

///

/// info | 说明

注意，`response_description` 只用于描述响应，`description` 一般则用于描述*路径操作*。

///

/// check | 检查

OpenAPI 规定每个*路径操作*都要有响应描述。

如果没有定义响应描述，**FastAPI** 则自动生成内容为 "Successful response" 的响应描述。

///

<img src="/img/tutorial/path-operation-configuration/image03.png">

## 弃用*路径操作*

`deprecated` 参数可以把*路径操作*标记为<abbr title="过时，建议不要使用">弃用</abbr>，无需直接删除：

                && Objects.equals(getPath(), other.getPath()) && Objects.equals(getPathConsumed(), other.getPathConsumed());
    }

    /**
     * Set the referral data from a referral response
     *
     * @param ref the referral response
     * @param reqPath the requested path
     * @param expire the expiration time
     * @param consumed the number of characters consumed from the path
     * @return referral data
     */

				"X-Amz-SignedHeaders":   "host;x-amz-content-sha256;x-amz-date",
				"X-Amz-Credential":      fmt.Sprintf(credentialTemplate, accessKeyID, now.Format(yyyymmdd), region),
				"X-Amz-Content-Sha256":  payloadSHA256,
				"response-content-type": "application/json",
			},
			headers: map[string]string{
				"X-Amz-Date":           now.Format(iso8601Format),
				"X-Amz-Content-Sha256": payloadSHA256,
			},
			region:   "",

        // Mock the negotiation response
        when(negotiationResponse.isSigningRequired()).thenReturn(false);
        when(negotiationResponse.isSigningNegotiated()).thenReturn(false);
        when(negotiationResponse.canReuse(any(CIFSContext.class), anyBoolean())).thenReturn(true);

        // Use reflection to set the negotiated response

      }
    }

  /**
   * An HTTP/2 response cannot contain uppercase header characters and must be treated as
   * malformed.
   */
  @Throws(IOException::class)
  fun checkLowercase(name: ByteString): ByteString {
    for (i in 0 until name.size) {
      if (name[i] in 'A'.code.toByte()..'Z'.code.toByte()) {
        throw IOException("PROTOCOL_ERROR response malformed: mixed case name: ${name.utf8()}")
      }
    }

			// 	If-None-Match condition evaluates to false , and;
			//  If-Modified-Since condition evaluates to true ;
			// 	Then Amazon S3 returns the 304 Not Modified response code.
			// 2. If If-Modified-Since condition evaluates to false, The following `ifModifiedSinceHeader` judgment will also return 304

			// If the object ETag matches with the specified ETag.

{* ../../docs_src/header_params/tutorial003_an_py310.py hl[9] *}

If you communicate with that *path operation* sending two HTTP headers like:

```
X-Token: foo
X-Token: bar
```

The response would be like:

```JSON
{
    "X-Token values": [
        "bar",
        "foo"
    ]
}
```

## Recap { #recap }

Il est tout de même possible d'utiliser `BackgroundTask` seul dans **FastAPI**, mais dans ce cas il faut créer l'objet dans le code et renvoyer une `Response` Starlette l'incluant.

			Message:    fmt.Sprintf("No response from server to download URL %s", u),
			StatusCode: http.StatusInternalServerError,
		}
	}
	defer xhttp.DrainBody(resp.Body)

	if resp.StatusCode != http.StatusOK {
		return content, AdminError{
			Code:       AdminUpdateUnexpectedFailure,
			Message:    fmt.Sprintf("Error downloading URL %s. Response: %v", u, resp.Status),
			StatusCode: resp.StatusCode,
		}