return sys.store.GetBucketUsers(bucket)
	case <-ctx.Done():
		return nil, ctx.Err()
	}
}

// ListUsers - list all users.
func (sys *IAMSys) ListUsers(ctx context.Context) (map[string]madmin.UserInfo, error) {
	if !sys.Initialized() {
		return nil, errServerNotInitialized
	}
	select {
	case <-sys.configLoaded:
		return sys.store.GetUsers(), nil
	case <-ctx.Done():
		return nil, ctx.Err()
	}
}

app = FastAPI()


class Item(BaseModel):
    name: str
    price: float
    is_offer: Union[bool, None] = None


@app.get("/")
def read_root():
    return {"Hello": "World"}


@app.get("/items/{item_id}")
def read_item(item_id: int, q: Union[str, None] = None):
    return {"item_id": item_id, "q": q}


@app.put("/items/{item_id}")
def update_item(item_id: int, item: Item):

	}

	rc, err := NewRepairController(client, cfg)
	if err != nil {
		repairLog.Fatalf("Fatal error constructing repair controller: %+v", err)
	}
	go rc.Run(ctx.Done())
	client.RunAndWait(ctx.Done())
}

// Set up Kubernetes client using kubeconfig (or in-cluster config if no file provided)
func clientSetup() (kube.Client, error) {
	config, err := kube.DefaultRestConfig("", "")
	if err != nil {

  }

  public void testReload() throws ExecutionException {
    final Object one = new Object();
    final Object two = new Object();
    CacheLoader<Object, Object> loader =
        new CacheLoader<Object, Object>() {
          @Override
          public Object load(Object key) {
            return one;
          }

          @Override

nr_servers=4

addr="localhost"
args=""
for ((i = 0; i < $((nr_servers)); i++)); do
	args="$args $scheme://$addr:$((9100 + i))/${HOME}/tmp/dist/path1/$i"
done

echo $args

for ((i = 0; i < $((nr_servers)); i++)); do
	(minio server --address ":$((9100 + i))" $args 2>&1 >/tmp/log$i.txt) &
done

sleep 10s

if [ ! -f ./mc ]; then
	wget --quiet -O ./mc https://dl.minio.io/client/mc/release/linux-amd64/./mc &&
		chmod +x mc
fi

     * @param severity The severity of the problem, must not be {@code null}.
     * @param message The detail message of the problem, may be {@code null}.
     * @param line The one-based index of the line containing the problem or {@code -1} if unknown.
     * @param column The one-based index of the column containing the problem or {@code -1} if unknown.
     * @param cause The cause of the problem, may be {@code null}.
     */

////

//// tab | Python 3.8+

```Python hl_lines="11  13-14"
{!> ../../docs_src/response_model/tutorial004.py!}
```

////

* `description: Union[str, None] = None` (oder `str | None = None` in Python 3.10) hat einen Defaultwert `None`.
* `tax: float = 10.5` hat einen Defaultwert `10.5`.
* `tags: List[str] = []` hat eine leere Liste als Defaultwert: `[]`.

    assertMultimapEquals(ImmutableListMultimap.of("one", 1), "one", 1);
    assertMultimapEquals(ImmutableListMultimap.of("one", 1, "two", 2), "one", 1, "two", 2);
    assertMultimapEquals(
        ImmutableListMultimap.of("one", 1, "two", 2, "three", 3), "one", 1, "two", 2, "three", 3);
    assertMultimapEquals(
        ImmutableListMultimap.of("one", 1, "two", 2, "three", 3, "four", 4),
        "one",
        1,
        "two",
        2,

 * an {@code ArrayTable} concurrently and one of the threads modifies its value, there is no
 * guarantee that the new value will be fully visible to the other threads. To guarantee that
 * modifications are visible, synchronize access to the table. Unlike other {@code Table}
 * implementations, synchronization is unnecessary between a thread that writes to one cell and a
 * thread that reads from another.
 *

</div>

Isso significa que ele **sempre terá um valor**, só que às vezes o valor pode ser `None` (ou `null` em termos de JSON).

Isso quer dizer que, os clientes que usam sua API não precisam verificar se o valor existe ou não, eles podem **assumir que o campo sempre estará lá**, mas que em alguns casos terá o valor padrão de `None`.

A maneira de descrever isso no OpenAPI é marcar esse campo como **obrigatório**, porque ele sempre estará lá.