*
 * (We could consider releasing a listenablefuture:1.0.1 someday. But we would want to look into how
 * that affects users, especially users of the Android Gradle Plugin, since the plugin developers
 * put in a special hack for us: https://issuetracker.google.com/issues/131431257)
 */
@DoNotMock("Use the methods in Futures (like immediateFuture) or SettableFuture")
@NullMarked

If you want to read more about these encodings and form fields, head to the [<abbr title="Mozilla Developer Network">MDN</abbr> web docs for `POST`](https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/POST).

///

/// warning

# Install Visual Studio 2022 Build Tools + Compiler
SHELL ["cmd", "/S", "/C"]
# Packages, and component versions, can be found here:
# https://learn.microsoft.com/en-us/visualstudio/install/workload-component-id-vs-build-tools
RUN C:\TEMP\vs_community.exe \
        --quiet --wait --norestart --nocache \
        --add Microsoft.VisualStudio.Component.VC.Tools.x86.x64 \

# WebSockets { #websockets }

你可以在 **FastAPI** 中使用 [WebSockets](https://developer.mozilla.org/en-US/docs/Web/API/WebSockets_API)。

## 安裝 `websockets` { #install-websockets }

請先建立[虛擬環境](../virtual-environments.md)、啟用它，然後安裝 `websockets`（一個讓你更容易使用「WebSocket」通訊協定的 Python 套件）：

<div class="termy">

```console
$ pip install websockets

---> 100%
```

</div>

## WebSockets 用戶端 { #websockets-client }

		return false
	case cache.finished() && time.Since(cache.lastHandout) > 5*metacacheMaxClientWait:
		// Keep for 15 minutes after we last saw the client.
		// Since the cache is finished keeping it a bit longer doesn't hurt us.
		return false
	case cache.status == scanStateError || cache.status == scanStateNone:
		// Remove failed listings after 5 minutes.
		return time.Since(cache.lastUpdate) > 5*time.Minute
	}
	return true
}

* その後、`response` を返す前にさらに `response` を変更することもできます。

{* ../../docs_src/middleware/tutorial001_py310.py hl[8:9,11,14] *}

/// tip | 豆知識

カスタムの独自ヘッダーは [`X-` プレフィックスを使用](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers)して追加できる点に注意してください。

        return bwcEnabled == null || (Boolean) bwcEnabled;
    }

    // TODO: implement custom extension that allows us move around of the projects between major versions and still find them
    private Path getCompatProjectPath(Project project, Path checkoutDir) {

    server.enqueue(MockResponse().setBody("hello world"))
    val url = server.url("/").toUrl()
    val connection = url.openConnection() as HttpURLConnection
    connection.setRequestProperty("Accept-Language", "en-US")
    val inputStream = connection.inputStream
    val reader = BufferedReader(InputStreamReader(inputStream, StandardCharsets.UTF_8))
    assertThat(connection.getResponseCode()).isEqualTo(HttpURLConnection.HTTP_OK)

    checkNotNull(executor, "Executor was null.");

    // Lock while we check state. We must maintain the lock while adding the new pair so that
    // another thread can't run the list out from under us. We only add to the list if we have not
    // yet started execution.
    synchronized (lock) {
      if (!executed) {
        runnables = new RunnableExecutorPair(runnable, executor, runnables);
        return;
      }

      safeMax = -1;
      safeMin = Integer.MAX_VALUE;
    }
    this.safeMin = safeMin;
    this.safeMax = safeMax;

    // This is a bit of a hack but lets us do quicker per-character checks in
    // the fast path code. The safe min/max values are very unlikely to extend
    // into the range of surrogate characters, but if they do we must not test