sequenceDiagram
    participant Client
    participant Proxy as Proxy/Load Balancer
    participant Server as FastAPI Server

    Client->>Proxy: HTTPS Request<br/>Host: mysuperapp.com<br/>Path: /items

    Note over Proxy: Proxy adds forwarded headers

    Proxy->>Server: HTTP Request<br/>X-Forwarded-For: [client IP]<br/>X-Forwarded-Proto: https<br/>X-Forwarded-Host: mysuperapp.com<br/>Path: /items

    "foo",
    "bar"
  ]
}
```

/// tip

To declare a query parameter with a type of `list`, like in the example above, you need to explicitly use `Query`, otherwise it would be interpreted as a request body.

///

The interactive API docs will update accordingly, to allow multiple values:

<img src="/img/tutorial/query-params-str-validations/image02.png">

```
KEY:
etcd  federate multiple clusters for IAM and Bucket DNS

ARGS:

    // Search Execute
    //

    /**
     * Performs bulk document operations (index multiple documents).
     * Validates document fields and adds default values where necessary.
     *
     * @param body the bulk request body containing documents to process
     * @return JSON response with bulk operation results
     */
    // PUT /api/admin/documents/bulk
    @Execute
    public JsonResponse<ApiResult> put$bulk(final BulkBody body) {

                                    </div>
                                </div>
                                <c:set var="pager" value="${charMappingPager}"
                                       scope="request"/>
                                <div class="row">
                                    <div class="col-sm-2">
                                        <la:message key="labels.pagination_page_guide_msg"

import static java.util.Objects.requireNonNull;

/**
 * Collects settings that control the building of effective settings.
 */
@Experimental
@Immutable
public interface SettingsBuilderRequest extends Request<ProtoSession> {

    /**
     * Gets the installation settings source.
     *
     * @return the installation settings source or {@code null} if none
     */
    @Nonnull

	file, err := os.Open(mountFilePath)
	if err != nil {
		return nil, err
	}
	defer file.Close()
	return parseMountFrom(file)
}

func parseMountFrom(file io.Reader) (mountInfos, error) {
	mounts := mountInfos{}
	scanner := bufio.NewReader(file)
	for {
		line, err := scanner.ReadString('\n')
		if err == io.EOF {
			break
		}

		fields := strings.Fields(line)

When building web APIs with FastAPI, if there's an error in our code, FastAPI will normally contain it to the single request that triggered the error. 🛡

The client will get a **500 Internal Server Error** for that request, but the application will continue working for the next requests instead of just crashing completely.

### Bigger Errors - Crashes { #bigger-errors-crashes }

-   [A nice collection](https://www.tfnico.com/presentations/google-guava) of
    other helpful links

## Links

-   [GitHub project](https://github.com/google/guava)
-   [Issue tracker: Report a defect or feature request](https://github.com/google/guava/issues/new)
-   [StackOverflow: Ask "how-to" and "why-didn't-it-work" questions](https://stackoverflow.com/questions/ask?tags=guava+java)

它被直接导入/包含到FastAPI以便你可以从 `fastapi` 导入，并避免意外从 `starlette.background` 导入备用的 `BackgroundTask` (后面没有 `s`)。

通过仅使用 `BackgroundTasks` (而不是 `BackgroundTask`)，使得能将它作为 *路径操作函数* 的参数 ，并让**FastAPI**为您处理其余部分, 就像直接使用 `Request` 对象。

在FastAPI中仍然可以单独使用 `BackgroundTask`，但您必须在代码中创建对象，并返回包含它的Starlette `Response`。