public String @Nullable [] foo() { return new String[] {"some", null}; }
                }
            """
        ) {
            assertHasErrors(
                "Field nonFinalField: Nullability breaking change.",
                "Field finalField: From non-nullable to nullable breaking change.",
                "Method com.example.Source.foo(): From non-null returning to null returning breaking change."
            )

@dataclass
class Dependant:
    path_params: list[ModelField] = field(default_factory=list)
    query_params: list[ModelField] = field(default_factory=list)
    header_params: list[ModelField] = field(default_factory=list)
    cookie_params: list[ModelField] = field(default_factory=list)
    body_params: list[ModelField] = field(default_factory=list)
    dependencies: list["Dependant"] = field(default_factory=list)
    name: Optional[str] = None

func (z *WalkDirOptions) DecodeMsg(dc *msgp.Reader) (err error) {
	var field []byte
	_ = field
	var zb0001 uint32
	zb0001, err = dc.ReadMapHeader()
	if err != nil {
		err = msgp.WrapError(err)
		return
	}
	for zb0001 > 0 {
		zb0001--
		field, err = dc.ReadMapKeyPtr()
		if err != nil {
			err = msgp.WrapError(err)
			return
		}
		switch msgp.UnsafeString(field) {
		case "Bucket":
			z.Bucket, err = dc.ReadString()

                                "` structure with `struct_size` field "   \
                                "set to " #SIZE_VALUE_NAME                \
                                ". Found `struct_size` = 0.");            \
    }                                                                     \
  } while (0)

// Macro to verify that the field NAME of STRUCT_OBJ is not null.

from sqlmodel import Field, Session, SQLModel, create_engine

engine = create_engine("postgresql+psycopg://postgres:postgres@localhost/db")


class User(SQLModel, table=True):
    id: int | None = Field(default=None, primary_key=True)
    name: str


app = FastAPI()


def get_session():
    with Session(engine) as session:
        yield session

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

            {
                "loc": ["body", "name"],
                "input": {},
                "msg": "Field required",
                "type": "missing",
            },
            {
                "loc": ["body", "price"],
                "input": {},
                "msg": "Field required",
                "type": "missing",
            },
            {
                "loc": ["body", "items"],

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

from typing import Annotated

from fastapi import Body, FastAPI
from pydantic import BaseModel, Field

app = FastAPI()


class Item(BaseModel):
    name: str
    description: str | None = Field(
        default=None, title="The description of the item", max_length=300
    )
    price: float = Field(gt=0, description="The price must be greater than zero")
    tax: float | None = None


@app.put("/items/{item_id}")

{* ../../docs_src/separate_openapi_schemas/tutorial001_py310.py ln[1:15] hl[14] *}

...then the `description` field will **not be required**. Because it has a default value of `None`.

### Input Model in Docs { #input-model-in-docs }

You can confirm that in the docs, the `description` field doesn't have a **red asterisk**, it's not marked as required:

<div class="screenshot">