.dns { hostname -> InetAddress.getAllByName(hostname).toList() }
    .build()
```

Kotlin calling OkHttp 4.x:

```kotlin
val client = OkHttpClient.Builder()
    .dns(object : Dns {
      override fun lookup(hostname: String) =
          InetAddress.getAllByName(hostname).toList()
    })
    .build()
```

SAM conversion impacts these APIs:

 * Authenticator
 * Dispatcher.setIdleCallback(Runnable)

---

"_I’m over the moon excited about **FastAPI**. It’s so fun!_"

That demonstrates how the Proxy (Traefik) uses the path prefix and how the server (Uvicorn) uses the `root_path` from the option `--root-path`.

### Check the docs UI

But here's the fun part. ✨

---

"_I’m over the moon excited about **FastAPI**. It’s so fun!_"

```Python
q: Annotated[Union[str, None]] = None
```

////

Both of those versions mean the same thing, `q` is a parameter that can be a `str` or `None`, and by default, it is `None`.

Now let's jump to the fun stuff. 🎉

## Add `Query` to `Annotated` in the `q` parameter

---

"_I’m over the moon excited about **FastAPI**. It’s so fun!_"

---

"_I’m over the moon excited about **FastAPI**. It’s so fun!_"

---

"_I’m over the moon excited about **FastAPI**. It’s so fun!_"

---

"_I’m over the moon excited about **FastAPI**. It’s so fun!_"

 [dev_server]: https://github.com/square/okhttp/blob/482f88300f78c3419b04379fc26c3683c10d6a9d/samples/guide/src/main/java/okhttp3/recipes/kt/DevServer.kt
 [fun_interface]: https://kotlinlang.org/docs/reference/fun-interfaces.html
 [iana_websocket]: https://www.iana.org/assignments/websocket/websocket.txt
 [jetty_8_252]: https://webtide.com/jetty-alpn-java-8u252/
 [kotlin_1_3_71]: https://github.com/JetBrains/kotlin/releases/tag/v1.3.71