m.Set("map1", &m1)
	m1.Add("a", 1)
	m1.Add("z", 2)
	m.Set("map2", &m2)
	for i := 0; i < 9; i++ {
		m2.Add(strconv.Itoa(i), int64(i))
	}
	var s1, s2 String
	m.Set("str1", &s1)
	s1.Set("hello, world!")
	m.Set("str2", &s2)
	s2.Set("fizz buzz")
	b.ResetTimer()

	b.ReportAllocs()
	for i := 0; i < b.N; i++ {
		_ = m.String()
	}
}

func BenchmarkRealworldExpvarUsage(b *testing.B) {

func lcpSuffix(strs []string) string {
	return lcp(strs, false)
}

func lcp(strs []string, pre bool) string {
	// short-circuit empty list
	if len(strs) == 0 {
		return ""
	}
	xfix := strs[0]
	// short-circuit single-element list
	if len(strs) == 1 {
		return xfix
	}
	// compare first to rest
	for _, str := range strs[1:] {
		xfixl := len(xfix)
		strl := len(str)

}

// Get the server port from server.URL (e.g., https://127.0.0.1:36253)
func getServerPort(server *httptest.Server) (int, error) {
	strs := strings.Split(server.URL, ":")
	if len(strs) < 2 {
		return 0, fmt.Errorf("server.URL is invalid: %v", server.URL)
	}
	port, err := strconv.Atoi(strs[len(strs)-1])
	if err != nil {
		return 0, fmt.Errorf("error to extract port from URL: %v", server.URL)
	}
	return port, nil
}

			query:    "foo:12345",
			location: expectedIP + ":12345",
		},
		{
			pod: api.Pod{
				ObjectMeta: metav1.ObjectMeta{Name: "foo"},
				Spec: api.PodSpec{
					Containers: []api.Container{
						{Name: "ctr1"},
						{Name: "ctr2", Ports: []api.ContainerPort{{ContainerPort: 9376}}},
					},
				},
				Status: api.PodStatus{PodIPs: []api.PodIP{{IP: expectedIP}}},
			},
			query:    "foo",

    ```

The query parameter `q` is of type `Union[str, None]` (or `str | None` in Python 3.10), that means that it's of type `str` but could also be `None`, and indeed, the default value is `None`, so FastAPI will know it's not required.

!!! note
    FastAPI will know that the value of `q` is not required because of the default value `= None`.

			need++
		}
	}
	if need == len(s) {
		return n
	}
	if need == 1 {
		var strs []string
		for _, c := range s {
			strs = append(strs, ir.StringVal(c))
		}
		return ir.NewConstExpr(constant.MakeString(strings.Join(strs, "")), n)
	}
	newList := make([]ir.Node, 0, need)
	for i := 0; i < len(s); i++ {

		slice.SetType(s.Type())
		slice.SetBounded(true)

		ptr1, len1 := backingArrayPtrLen(cheapExpr(slice, &nodes))
		ptr2, len2 := backingArrayPtrLen(l2)

		fn := typecheck.LookupRuntime("slicecopy", ptr1.Type().Elem(), ptr2.Type().Elem())
		ncopy = mkcall1(fn, types.Types[types.TINT], &nodes, ptr1, len1, ptr2, len2, ir.NewInt(base.Pos, elemtype.Size()))
	} else {

    {!> ../../../docs_src/query_params_str_validations/tutorial001_py310.py!}
    ```

🔢 🔢 `q` 🆎 `Union[str, None]` (⚖️ `str | None` 🐍 3️⃣.1️⃣0️⃣), 👈 ⛓ 👈 ⚫️ 🆎 `str` ✋️ 💪 `None`, & 👐, 🔢 💲 `None`, FastAPI 🔜 💭 ⚫️ 🚫 ✔.

!!! note
    FastAPI 🔜 💭 👈 💲 `q` 🚫 ✔ ↩️ 🔢 💲 `= None`.

     `Union` `Union[str, None]` 🔜 ✔ 👆 👨‍🎨 🤝 👆 👍 🐕‍🦺 & 🔍 ❌.

## 🌖 🔬

=== "Python 3.10+"

    ```Python
    q: str | None = None
    ```

=== "Python 3.8+"

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

Вот что мы получим, если обернём это в `Annotated`:

=== "Python 3.10+"

    ```Python
    q: Annotated[str | None] = None
    ```

=== "Python 3.8+"

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

    ```

Der Query-Parameter `q` hat den Typ `Union[str, None]` (oder `str | None` in Python 3.10), was bedeutet, er ist entweder ein `str` oder `None`. Der Defaultwert ist `None`, also weiß FastAPI, der Parameter ist nicht erforderlich.

!!! note "Hinweis"
    FastAPI weiß nur dank des definierten Defaultwertes `=None`, dass der Wert von `q` nicht erforderlich ist