"loc": ["body", "username"],
                    "msg": "Field required",
                    "input": None,
                },
                {
                    "type": "missing",
                    "loc": ["body", "password"],
                    "msg": "Field required",
                    "input": None,
                },
            ]
        }
    ) | IsDict(
        # TODO: remove when deprecating Pydantic v1

                    "loc": ["body", "username"],
                    "msg": "Field required",
                    "input": None,
                },
                {
                    "type": "missing",
                    "loc": ["body", "password"],
                    "msg": "Field required",
                    "input": None,
                },
            ]
        }
    ) | IsDict(
        # TODO: remove when deprecating Pydantic v1

                    "loc": ["body", "username"],
                    "msg": "Field required",
                    "input": None,
                },
                {
                    "type": "missing",
                    "loc": ["body", "password"],
                    "msg": "Field required",
                    "input": None,
                },
            ]
        }
    ) | IsDict(

                    "loc": ["body", "file"],
                    "msg": "Field required",
                    "input": None,
                },
                {
                    "type": "missing",
                    "loc": ["body", "fileb"],
                    "msg": "Field required",
                    "input": None,
                },
                {
                    "type": "missing",

        return str(obj)
    if isinstance(obj, (str, int, float, type(None))):
        return obj
    if isinstance(obj, UndefinedType):
        return None
    if isinstance(obj, dict):
        encoded_dict = {}
        allowed_keys = set(obj.keys())
        if include is not None:
            allowed_keys &= set(include)
        if exclude is not None:
            allowed_keys -= set(exclude)

app = FastAPI()


class Item(BaseModel):
    name: str
    description: Union[str, None] = None
    price: float
    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": []},
}

    return client


@needs_py39
def test_create_item(client: TestClient) -> None:
    response = client.post("/items/", json={"name": "Foo"})
    assert response.status_code == 200, response.text
    assert response.json() == {"name": "Foo", "description": None}


@needs_py39
def test_read_items(client: TestClient) -> None:
    response = client.get("/items/")
    assert response.status_code == 200, response.text

from typing import Annotated

from fastapi import Body, FastAPI
from pydantic import BaseModel

app = FastAPI()


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


@app.put("/items/{item_id}")
async def update_item(
    *,
    item_id: int,
    item: Annotated[
        Item,
        Body(
            openapi_examples={

        def serialize(
            self,
            value: Any,
            *,
            mode: Literal["json", "python"] = "json",
            include: Union[IncEx, None] = None,
            exclude: Union[IncEx, None] = None,
            by_alias: bool = True,
            exclude_unset: bool = False,
            exclude_defaults: bool = False,
            exclude_none: bool = False,
        ) -> Any:

app = FastAPI()


@app.get("/hidden_cookie")
async def hidden_cookie(
    hidden_cookie: Optional[str] = Cookie(default=None, include_in_schema=False),
):
    return {"hidden_cookie": hidden_cookie}


@app.get("/hidden_header")
async def hidden_header(
    hidden_header: Optional[str] = Header(default=None, include_in_schema=False),
):
    return {"hidden_header": hidden_header}


@app.get("/hidden_path/{hidden_path}")