name: str
        description: Optional[str] = None
        foo: ModelB

        @field_validator("name")
        def lower_username(cls, name: str, info: ValidationInfo):
            if not name.endswith("A"):
                raise ValueError("name must end in A")
            return name

    async def get_model_c() -> ModelC:
        return ModelC(username="test-user", password="test-password")

                                if message.get_content_maintype() == "application":
                                    subtype = message.get_content_subtype()
                                    if subtype == "json" or subtype.endswith("+json"):
                                        json_body = await request.json()
                            if json_body != Undefined:
                                body = json_body
                            else: