/// note

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

The `str | None` (Python 3.10+) or `Union` in `Union[str, None]` (Python 3.9+) is not used by FastAPI to determine that the value is not required, it will know it's not required because it has a default value of `= None`.

But adding the type annotations will allow your editor to give you better support and detect errors.

///

    return new TrackedRunnable() {
      private volatile boolean done = false;

      @Override
      public boolean isDone() {
        return done;
      }

      @Override
      public void run() {
        try {
          delay(timeoutMillis);
          done = true;
        } catch (InterruptedException ok) {
        }
      }
    };
  }

## Paramètres optionnels

De la même façon, vous pouvez définir des paramètres de requête comme optionnels, en leur donnant comme valeur par défaut `None` :

{* ../../docs_src/query_params/tutorial002.py hl[9] *}

Ici, le paramètre `q` sera optionnel, et aura `None` comme valeur par défaut.

/// check | Remarque

    font-size: 10pt;
    color: #000000;
    text-decoration: none
}
a.plain {
    display: inline;
    float: none;
    width: auto;
    height: auto
}
a.sort {
    display: block;
    float: left;
    width: 100px;
    height: 15px;
    font-family: Verdana, sans-serif;
    font-size: 8pt;
    font-weight: bold;
    text-decoration: none;
    color: #000000;
    background-color: #d0d0d0;

	docker-compose -f docker-compose-site1.yaml rm -s -f || true
	docker-compose -f docker-compose-site2.yaml rm -s -f || true
	for volume in $(docker volume ls -q | grep minio); do
		docker volume rm ${volume} || true
	done

	docker system prune -f || true
	docker volume prune -f || true
	docker volume rm $(docker volume ls -q -f dangling=true) || true
}

cleanup

if [ ! -f ./mc ]; then

      checkNotDone();
      digest.update(bytes);
    }

    private void checkNotDone() {
      checkState(!done, "Cannot re-use a Hasher after calling hash() on it");
    }

    @Override
    public HashCode hash() {
      checkNotDone();
      done = true;
      return (bytes == digest.getDigestLength())
          ? HashCode.fromBytesNoCopy(digest.digest())

// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package csv

import (
	"encoding/xml"
	"errors"
	"fmt"
	"io"
	"strings"
	"unicode/utf8"
)

const (
	none   = "none"
	use    = "use"
	ignore = "ignore"

	defaultRecordDelimiter      = "\n"
	defaultFieldDelimiter       = ","
	defaultQuoteCharacter       = `"`
	defaultQuoteEscapeCharacter = `"`

| <<<pom>>>             |               | <= type>   | none      |                       |                       |
*-----------------------+---------------+------------+-----------+-----------------------+-----------------------+
| <<<bom>>> *           |               | <<<pom>>>  | none      |                       |                       |

    client = TestClient(mod.app)
    return client


@pytest.mark.parametrize(
    "path,headers,expected_status,expected_response",
    [
        ("/items", None, 200, {"X-Token values": None}),
        ("/items", {"x-token": "foo"}, 200, {"X-Token values": ["foo"]}),
        (
            "/items",
            [("x-token", "foo"), ("x-token", "bar")],
            200,

def test_union_body_discriminator_assignment(client: TestClient) -> None:
    response = client.post("/pet/assignment", json={"pet_type": "cat", "meows": 5})
    assert response.status_code == 200, response.text
    assert response.json() == {"pet_type": "cat", "meows": 5}


def test_union_body_discriminator_annotated(client: TestClient) -> None:
    response = client.post("/pet/annotated", json={"pet_type": "dog", "barks": 3.5})