ref: Optional[str] = Field(default=None, alias="$ref")
    dynamicRef: Optional[str] = Field(default=None, alias="$dynamicRef")
    defs: Optional[dict[str, "SchemaOrBool"]] = Field(default=None, alias="$defs")
    comment: Optional[str] = Field(default=None, alias="$comment")
    # Ref: JSON Schema 2020-12: https://json-schema.org/draft/2020-12/json-schema-core.html#name-a-vocabulary-for-applying-s

app = FastAPI()


@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}
```

<details markdown="1">
<summary>Oder verwenden Sie <code>async def</code> ...</summary>

Wenn Ihr Code `async` / `await` verwendet, benutzen Sie `async def`:

```Python hl_lines="9  14"

@app.post("/sync/validated", response_model=ItemOut)
def sync_validated(item: ItemIn, dep: Annotated[int, Depends(dep_b)]):
    return ItemOut(name=item.name, value=item.value, dep=dep)


@app.get("/sync/dict-no-response-model")
def sync_dict_no_response_model():
    return {"name": "foo", "value": 123}


@app.get("/sync/dict-with-response-model", response_model=ItemOut)
def sync_dict_with_response_model(

@app.post("/optional-list-str", operation_id="optional_list_str")
async def read_optional_list_str(
    p: Annotated[Optional[list[str]], Form()] = None,
):
    return {"p": p}


class FormModelOptionalListStr(BaseModel):
    p: Optional[list[str]] = None


@app.post("/model-optional-list-str", operation_id="model_optional_list_str")
async def read_model_optional_list_str(p: Annotated[FormModelOptionalListStr, Form()]):

        if isinstance(cls, WithArgsTypes):
            return False
        raise  # pragma: no cover


def _annotation_is_sequence(annotation: Union[type[Any], None]) -> bool:
    if lenient_issubclass(annotation, (str, bytes)):
        return False
    return lenient_issubclass(annotation, sequence_types)


def field_annotation_is_sequence(annotation: Union[type[Any], None]) -> bool:
    origin = get_origin(annotation)

class Item(BaseModel):
    data: str


def duplicate_dependency(item: Item):
    return item


def dependency(item2: Item):
    return item2


def sub_duplicate_dependency(
    item: Item, sub_item: Item = Depends(duplicate_dependency)
):
    return [item, sub_item]


@app.post("/with-duplicates")
async def with_duplicates(item: Item, item2: Item = Depends(duplicate_dependency)):

from fastapi.testclient import TestClient
from pydantic import BaseModel, ConfigDict


def create_app():
    app = FastAPI()

    class Item(BaseModel):
        data: str

        model_config = ConfigDict(
            json_schema_extra={"example": {"data": "Data in schema_extra"}}
        )

    @app.post("/schema_extra/")
    def schema_extra(item: Item):
        return item

        pytest.param("tutorial002_py39"),
        pytest.param("tutorial002_py310", marks=needs_py310),
    ],
)
def get_client(request: pytest.FixtureRequest):
    mod = importlib.import_module(f"docs_src.body_multiple_params.{request.param}")

    client = TestClient(mod.app)
    return client


def test_post_all(client: TestClient):
    response = client.put(
        "/items/5",
        json={
            "item": {

            _invalid_args_message.format(type_=type_)
        ) from None


def create_cloned_field(
    field: ModelField,
    *,
    cloned_types: Optional[MutableMapping[type[BaseModel], type[BaseModel]]] = None,
) -> ModelField:
    return field


def generate_operation_id_for_path(
    *, name: str, path: str, method: str
) -> str:  # pragma: nocover
    warnings.warn(

    params=[
        pytest.param("tutorial006_py39"),
        pytest.param("tutorial006_an_py39"),
    ],
)
def get_client(request: pytest.FixtureRequest):
    mod = importlib.import_module(f"docs_src.dependencies.{request.param}")

    client = TestClient(mod.app)
    return client


def test_get_no_headers(client: TestClient):
    response = client.get("/items/")
    assert response.status_code == 422, response.text