return attrname in cls._CONSTRUCTOR_PARAMS
    @classmethod
    def _value_is_hardcoded_default(cls, attrname: str, value: Any, instance: Any) -> bool:
        """
        Return true if ``value`` is the hard-coded default for the given attribute.
        This takes in to account cases where the ``max_active_tasks`` parameter is
        stored in the ``_max_active_tasks`` attribute.
        And by using `is` here only and not `==` this copes with the case a
        user explicitly specifies an attribute with the same "value" as the
        default. (This is because ``"default" is "default"`` will be False as
        they are different strings with the same characters.)
        Also returns True if the value is an empty list or empty dict. This is done
        to account for the case where the default value of the field is None but has the
        ``field = field or {}`` set.
        """
        if attrname in cls._CONSTRUCTOR_PARAMS and (
            cls._CONSTRUCTOR_PARAMS[attrname] is value or (value in [{}, []])
        ):
            return True
        return False
    @classmethod
    def _serialize_param(cls, param: Param):
        return dict(
            __class=f"{param.__module__}.{param.__class__.__name__}",
            default=cls.serialize(param.value),
            description=cls.serialize(param.description),
            schema=cls.serialize(param.schema),
        )
    @classmethod
    def _deserialize_param(cls, param_dict: dict):