*
   * <p>Caches loaded by a {@link CacheLoader} will call {@link CacheLoader#reload} if the cache
   * currently contains a value for {@code key}, and {@link CacheLoader#load} otherwise. Loading is
   * asynchronous only if {@link CacheLoader#reload} was overridden with an asynchronous
   * implementation.
   *

  }

  @Synchronized override fun onReadPing(payload: ByteString) {
    // Don't respond to pings after we've failed or sent the close frame.
    if (failed || enqueuedClose && messageAndCloseQueue.isEmpty()) return

    pongQueue.add(payload)
    runWriter()
    receivedPingCount++
  }

  @Synchronized override fun onReadPong(payload: ByteString) {
    // This API doesn't expose pings.

Let's start with a simple FastAPI application:

{* ../../docs_src/generate_clients/tutorial001_py39.py hl[7:9,12:13,16:17,21] *}

Notice that the *path operations* define the models they use for request payload and response payload, using the models `Item` and `ResponseMessage`.

### API Docs { #api-docs }

If you go to `/docs`, you will see that it has the **schemas** for the data to be sent in requests and received in responses:

Pour exécuter l'un de ces exemples, copiez le code dans un fichier `main.py`, et commencez `uvicorn` avec :

<div class="termy">

```console
$ uvicorn main:app --reload

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
<span style="color: green;">INFO</span>:     Started reloader process [28720]

		// Test case with "X-Amz-Content-Sha256" not set so we can skip.
		{"", "", "", "", true},

		// Test case - 3.
		// Test case with "X-Amz-Content-Sha256" header set to  "UNSIGNED-PAYLOAD"
		// When "X-Amz-Content-Sha256" header is set to  "UNSIGNED-PAYLOAD", validation of content sha256 has to be skipped.
		{"X-Amz-Content-Sha256", unsignedPayload, "X-Amz-Credential", "", true},

		// Test case - 4.

                .result());
    }

    /**
     * Create a new character mapping entry for the specified dictionary.
     *
     * @param dictId identifier of the dictionary
     * @param body create request payload
     * @return JSON response containing creation result and new entry ID
     */
    // POST /api/admin/dict/mapping/setting/{dictId}
    @Execute

* body (meaning HTTP response body): тело ответа
* body parameter : body-параметр (or `параметр тела запроса`)
* validate: валидировать (or `выполнить валидацию`)
* requirements (meaning dependencies): зависимости
* auto-reload: авто-перезагрузка (or `перезагрузить автоматически` if used as a verb)
* show (meaning show on the screen): отобразить
* parsing (noun): парсинг
* origin (in web development): origin (add `источник` if clarification is needed)

```console
$ uvicorn main:app --reload

INFO:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
INFO:     Started reloader process [28720]
INFO:     Started server process [28722]
INFO:     Waiting for application startup.
INFO:     Application startup complete.
```

</div>

<details markdown="1">
<summary><code>uvicorn main:app --reload</code> 명령에 관하여...</summary>

### Test it { #test-it }

Now, you should be able to go to your docs at <a href="http://127.0.0.1:8000/docs" class="external-link" target="_blank">http://127.0.0.1:8000/docs</a>, and reload the page, it will load those assets from the new CDN.

## Self-hosting JavaScript and CSS for docs { #self-hosting-javascript-and-css-for-docs }

   * of refreshes are specified in {@link LoadingCache#refresh}, and are performed by calling {@link
   * CacheLoader#reload}.
   *
   * <p>As the default implementation of {@link CacheLoader#reload} is synchronous, it is
   * recommended that users of this method override {@link CacheLoader#reload} with an asynchronous
   * implementation; otherwise refreshes will be performed during unrelated cache read and write
   * operations.