=== "Python 3.9+"

    ```Python hl_lines="14"
    {!> ../../../docs_src/request_files/tutorial001_an_py39.py!}
    ```

=== "Python 3.8+"

    ```Python hl_lines="13"
    {!> ../../../docs_src/request_files/tutorial001_an.py!}
    ```

=== "Python 3.8+ non-Annotated"

    !!! tip
        Prefer to use the `Annotated` version if possible.

    ```Python hl_lines="12"

		}
	}
	o = bts
	return
}

// Msgsize returns an upper bound estimate of the number of bytes occupied by the serialized message
func (z *MetricV2) Msgsize() (s int) {
	s = 1 + 12 + z.Description.Msgsize() + 13 + msgp.MapHeaderSize
	if z.StaticLabels != nil {
		for za0001, za0002 := range z.StaticLabels {
			_ = za0002
			s += msgp.StringPrefixSize + len(za0001) + msgp.StringPrefixSize + len(za0002)
		}
	}

```

:

=== "🐍 3️⃣.6️⃣ & 🔛"

    ```Python hl_lines="15"
    {!> ../../../docs_src/body_nested_models/tutorial008.py!}
    ```

=== "🐍 3️⃣.9️⃣ & 🔛"

    ```Python hl_lines="13"
    {!> ../../../docs_src/body_nested_models/tutorial008_py39.py!}
    ```

## 👨‍🎨 🐕‍🦺 🌐

& 👆 🤚 👨‍🎨 🐕‍🦺 🌐.

🏬 🔘 📇:

<img src="/img/tutorial/body-nested-models/image01.png">

  optional SupplementalGroupsStrategyOptions supplementalGroups = 12;

  // fsGroup is the strategy that will dictate what fs group is used by the SecurityContext.
  optional FSGroupStrategyOptions fsGroup = 13;

  // readOnlyRootFilesystem when set to true will force containers to run with a read only root file
  // system.  If the container specifically requests to run with a non-read only root file system

    val request =
      originalRequest.newBuilder()
        .header("Upgrade", "websocket")
        .header("Connection", "Upgrade")
        .header("Sec-WebSocket-Key", key)
        .header("Sec-WebSocket-Version", "13")
        .header("Sec-WebSocket-Extensions", "permessage-deflate")
        .build()
    call = RealCall(webSocketClient, request, forWebSocket = true)
    call!!.enqueue(
      object : Callback {

func (z *ErasureInfo) Msgsize() (s int) {
	s = 1 + 10 + msgp.StringPrefixSize + len(z.Algorithm) + 11 + msgp.IntSize + 13 + msgp.IntSize + 10 + msgp.Int64Size + 6 + msgp.IntSize + 13 + msgp.ArrayHeaderSize + (len(z.Distribution) * (msgp.IntSize)) + 10 + msgp.ArrayHeaderSize
	for za0002 := range z.Checksums {
		s += z.Checksums[za0002].Msgsize()
	}
	return
}

🖼, 👆 💪 ✔️ 📁 `config.py` ⏮️:

```Python
{!../../../docs_src/settings/app01/config.py!}
```

& ⤴️ ⚙️ ⚫️ 📁 `main.py`:

```Python hl_lines="3  11-13"
{!../../../docs_src/settings/app01/main.py!}
```

!!! tip
    👆 🔜 💪 📁 `__init__.py` 👆 👀 🔛 [🦏 🈸 - 💗 📁](../tutorial/bigger-applications.md){.internal-link target=_blank}.

## ⚒ 🔗

=== "Python 3.10+"

    In Python 3.9 or above, `Annotated` is part of the standard library, so you can import it from `typing`.

    ```Python hl_lines="1  3"
    {!> ../../../docs_src/query_params_str_validations/tutorial002_an_py310.py!}
    ```

=== "Python 3.8+"

    In versions of Python below Python 3.9 you import `Annotated` from `typing_extensions`.

You can create the *path operations* for that module using `APIRouter`.

### Import `APIRouter`

You import it and create an "instance" the same way you would with the class `FastAPI`:

```Python hl_lines="1  3" title="app/routers/users.py"
{!../../../docs_src/bigger_applications/app/routers/users.py!}
```

### *Path operations* with `APIRouter`

And then you use it to declare your *path operations*.

    assertEquals(SOME_COLLECTION, list);
  }

  public void testComputeArrayListCapacity() {
    assertEquals(5, Lists.computeArrayListCapacity(0));
    assertEquals(13, Lists.computeArrayListCapacity(8));
    assertEquals(89, Lists.computeArrayListCapacity(77));
    assertEquals(22000005, Lists.computeArrayListCapacity(20000000));