Par exemple, le modèle ci-dessus déclare un JSON « `object` » (ou `dict` Python) tel que :

```JSON
{
    "name": "Foo",
    "description": "An optional description",
    "price": 45.2,
    "tax": 3.5
}
```

... `description` et `tax` étant des attributs optionnels (avec `None` comme valeur par défaut), ce JSON « `object` » serait aussi valide :

```JSON
{

	"gopkg.in/yaml.v3"
)

// expire: # Expire objects that match a condition
//   apiVersion: v1
//   bucket: mybucket # Bucket where this batch job will expire matching objects from
//   prefix: myprefix # (Optional) Prefix under which this job will expire objects matching the rules below.
//   rules:
//     - type: object  # regular objects with zero or more older versions

 * Parses a given XML file, applies a set of changes, and writes those changes back to the original file.
 *
 * @param path Path to existing XML file
 * @param action Action to perform on parsed XML document
 * @param preface optional front matter to add after the XML declaration
 * but before the XML document, e.g. a doctype or comment
 */
void modifyXml(Object path, Action<? super Node> action, String preface = null) {
  Node xml = parseXml(path)

                    Artifact artifact = node.getArtifact();

                    try {
                        if (node.filterTrail(filter)) {
                            // If it was optional and not a direct dependency,
                            // we don't add it or its children, just allow the update of the version and artifactScope
                            if (node.isChildOfRootNode() || !artifact.isOptional()) {

 * to add or remove multiple occurrences of an element at once, or to set the count of an element to
 * a specific value. These modification operations are optional, but implementations which support
 * the standard collection operations {@link #add(Object)} or {@link #remove(Object)} are encouraged
 * to implement the related methods as well. Finally, two collection views are provided: {@link

    * чрезвычайно простые тесты на основе HTTPX и `pytest`
    * **CORS**
    * **сессии с использованием cookie**
    * ...и многое другое.

### Разверните приложение (опционально) { #deploy-your-app-optional }

При желании вы можете развернуть своё приложение FastAPI в [FastAPI Cloud](https://fastapicloud.com), присоединяйтесь к списку ожидания, если ещё не сделали этого. 🚀

* 许多额外特性（归功于 Starlette），例如：
    * **WebSockets**
    * 基于 HTTPX 和 `pytest` 的极其简单的测试
    * **CORS**
    * **Cookie Sessions**
    * ……以及更多。

### 部署你的应用（可选） { #deploy-your-app-optional }

你可以选择把 FastAPI 应用部署到 [FastAPI Cloud](https://fastapicloud.com)，如果还没有的话去加入候补名单吧。🚀

如果你已经有 **FastAPI Cloud** 账号（我们从候补名单邀请了你 😉），你可以用一个命令部署你的应用。

<div class="termy">

```console
$ fastapi deploy

import org.codelibs.fess.Constants;
import org.codelibs.fess.dict.DictionaryException;
import org.codelibs.fess.dict.DictionaryFile;
import org.codelibs.fess.util.ComponentUtil;
import org.dbflute.optional.OptionalEntity;

/**
 * Character mapping file handler for managing character mapping dictionaries.
 * This class provides functionality to load, parse, and manage character mapping

 * accuracy, use {@code System.nanoTime()} directly instead.
 *
 * <p>Basic usage:
 *
 * {@snippet :
 * Stopwatch stopwatch = Stopwatch.createStarted();
 * doSomething();
 * stopwatch.stop(); // optional
 *
 * Duration duration = stopwatch.elapsed();
 *
 * log.info("time: " + stopwatch); // formatted string like "12.3 ms"
 * }
 *

## An app with callbacks { #an-app-with-callbacks }

Let's see all this with an example.

Imagine you develop an app that allows creating invoices.

These invoices will have an `id`, `title` (optional), `customer`, and `total`.

The user of your API (an external developer) will create an invoice in your API with a POST request.

Then your API will (let's imagine):