Undefined = PydanticUndefined
    UndefinedType = PydanticUndefinedType
    evaluate_forwardref = eval_type_lenient
    Validator = Any

    class BaseConfig:
        pass

    class ErrorWrapper(Exception):
        pass

    @dataclass
    class ModelField:
        field_info: FieldInfo
        name: str
        mode: Literal["validation", "serialization"] = "validation"

        @property