internal var eventListenerFactory: EventListener.Factory = EventListener.NONE.asFactory()
    internal var retryOnConnectionFailure = true
    internal var fastFallback = true
    internal var authenticator: Authenticator = Authenticator.NONE
    internal var followRedirects = true
    internal var followSslRedirects = true

}


class Token(BaseModel):
    access_token: str
    token_type: str


class TokenData(BaseModel):
    username: str | None = None


class User(BaseModel):
    username: str
    email: str | None = None
    full_name: str | None = None
    disabled: bool | None = None


class UserInDB(User):
    hashed_password: str


password_hash = PasswordHash.recommended()

]


class Author(BaseModel):
    login: str
    avatarUrl: str | None = None
    url: str | None = None


class CommentsNode(BaseModel):
    createdAt: datetime
    author: Author | None = None
    minimizedReason: LowerStr | None = None


class Replies(BaseModel):
    totalCount: int
    nodes: list[CommentsNode]

    [
        "array",
        ["string", "null"],
        None,
    ],
)
def test_allowed_schema_type(
    type_value: SchemaType | list[SchemaType] | None,
) -> None:
    """Test that Schema accepts SchemaType, List[SchemaType] and None for type field."""
    schema = Schema(type=type_value)
    assert schema.type == type_value


def test_invalid_type_value() -> None:

Nous avions cette annotation de type :

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

Ce que nous allons faire, c’est l’englober avec `Annotated`, de sorte que cela devienne :

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

Les deux versions signifient la même chose, `q` est un paramètre qui peut être une `str` ou `None`, et par défaut, c’est `None`.

Passons maintenant aux choses amusantes. 🎉

            "axisLabel": "",
            "axisPlacement": "auto",
            "barAlignment": 0,
            "drawStyle": "line",
            "fillOpacity": 10,
            "gradientMode": "none",
            "hideFrom": {
              "legend": false,
              "tooltip": false,
              "viz": false
            },
            "insertNulls": false,
            "lineInterpolation": "linear",

class Item(BaseModel):
    name: str
    description: str | None = None
    price: float
    tax: float | None = None


class User(BaseModel):
    username: str
    full_name: str | None = None


@app.put("/items/{item_id}")
async def update_item(
    *,
    item_id: int,
    item: Item,
    user: User,
    importance: int = Body(gt=0),
    q: str | None = None,
):

```Python
say_hi(name=None)  # Це працює, None припустимий 🎉
```

Гарна новина: у більшості випадків ви зможете просто використовувати `|`, щоб визначати об'єднання типів:

```python
def say_hi(name: str | None):
    print(f"Hey {name}!")
```

    status_code, body = _bench_post_json(
        benchmark,
        client,
        "/sync/validated",
        json={"name": "foo", "value": 123},
    )
    assert status_code == 200
    assert body == b'{"name":"foo","value":123,"dep":42}'


def test_sync_return_dict_without_response_model(benchmark, client: TestClient) -> None:

app = FastAPI()


class Item(BaseModel):
    name: str | None = None
    description: str | None = None
    price: float | None = None
    tax: float = 10.5
    tags: list[str] = []


items = {
    "foo": {"name": "Foo", "price": 50.2},
    "bar": {"name": "Bar", "description": "The bartenders", "price": 62, "tax": 20.2},
    "baz": {"name": "Baz", "description": None, "price": 50.2, "tax": 10.5, "tags": []},
}