```

////

As in this case (without using `Annotated`) we have to replace the default value `None` in the function with `Query()`, we now need to set the default value with the parameter `Query(default=None)`, it serves the same purpose of defining that default value (at least for FastAPI).

So:

```Python
q: Union[str, None] = Query(default=None)
```

通过以下命令运行服务器：

<div class="termy">

```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>关于 <code>uvicorn main:app --reload</code> 命令......</summary>

// nolint: unparam
func (z *ztunnelServer) handleConn(ctx context.Context, conn *ZtunnelConnection) error {
	defer conn.Close()

	context.AfterFunc(ctx, func() {
		log.Debug("context cancelled, closing ztunnel server")
		conn.Close()
	})

	// before doing anything, add the connection to the list of active connections
	z.conns.addConn(conn)
	defer z.conns.deleteConn(conn)

	// get hello message from ztunnel

     * @return The model cache or {@code null} if not set.
     */
    ModelCache getModelCache();

    /**
     * Sets the model cache to use for reuse of previously built models. This is an optional component that serves
     * performance optimizations.
     *
     * @param modelCache The model cache to use, may be {@code null}.
     * @return This request, never {@code null}.
     */

<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]
<span style="color: green;">INFO</span>:     Started server process [28722]
<span style="color: green;">INFO</span>:     Waiting for application startup.
<span style="color: green;">INFO</span>:     Application startup complete.
```

</div>

/// note | "備考"

Das ist auch bei den meisten Webanwendungen der Fall.

Viele, viele Benutzer, aber Ihr Server wartet 🕙 darauf, dass deren nicht so gute Internetverbindungen die Requests übermitteln.

Und dann warten 🕙, bis die Responses zurückkommen.

This is the case for most of the web applications.

Many, many users, but your server is waiting 🕙 for their not-so-good connection to send their requests.

And then waiting 🕙 again for the responses to come back.

⤴️ ⚫️ 🏗 🌐 👈 🔬 ⬜ 🕸 🔠 🇪🇸, 🌀 👫, & 🏗 🏁 🔢 `./site/`.

⤴️ 👆 💪 🍦 👈 ⏮️ 📋 `serve`:

<div class="termy">

```console
// Use the command "serve" after running "build-all"
$ python ./scripts/docs.py serve

Warning: this is a very simple server. For development, use mkdocs serve instead.
This is here only to preview a site with translations already built.

    --hash=sha256:a6df30f272c08bf8be66e0775fad862005d950a6b8449b94f7c788731d70ecd7
    # via -r ci/official/requirements_updater/requirements.in
tensorboard-data-server==0.7.2 \
    --hash=sha256:7e0610d205889588983836ec05dc098e80f97b7e7bbff7e994ebb78f578d0ddb \
    --hash=sha256:9fe5d24221b29625dbc7328b0436ca7fc1c23de4acf4d272f1180856e32f9f60 \

  /**
   * Invoked when a result is served from the cache. The Response provided is the top level
   * Response and normal event sequences will not be received.
   *
   * This event will only be received when a Cache is configured for the client.
   */
  open fun cacheHit(
    call: Call,
    response: Response,
  ) {
  }

  /**
   * Invoked when a response will be served from the network. The Response will be