How to use the jsons.exceptions.JsonsError function in jsons

def test_load_list_multithreaded(self):
        dat = datetime.datetime(year=2018, month=7, day=8, hour=21, minute=34,
                                tzinfo=datetime.timezone.utc)
        list_ = [1, 2, 3, [4, 5, [dat]]]
        expectation = [1, 2, 3, [4, 5, ['2018-07-08T21:34:00Z']]]
        self.assertEqual(list_, jsons.load(expectation, tasks=3,
                                           task_type=Thread))

        with self.assertRaises(JsonsError):
            jsons.load(expectation, tasks=-1,
                       task_type=Thread)

        self.assertEqual([1], jsons.load(['1'], List[int], tasks=2,
                                         task_type=Thread))

        # More tasks than elements should still work.
        self.assertEqual([1, 1, 1, 1], jsons.load(['1', '1', '1', '1'],
                                                  List[int], tasks=16,
                                                  task_type=Thread))

def default_union_deserializer(obj: object, cls: Union, **kwargs) -> object:
    """
    Deserialize an object to any matching type of the given union. The first
    successful deserialization is returned.
    :param obj: The object that needs deserializing.
    :param cls: The Union type with a generic (e.g. Union[str, int]).
    :param kwargs: Any keyword arguments that are passed through the
    deserialization process.
    :return: An object of the first type of the Union that could be
    deserialized successfully.
    """
    for sub_type in get_union_params(cls):
        try:
            return load(obj, sub_type, **kwargs)
        except JsonsError:
            pass  # Try the next one.
    else:
        args_msg = ', '.join([get_class_name(cls_)
                              for cls_ in get_union_params(cls)])
        err_msg = ('Could not match the object of type "{}" to any type of '
                   'the Union: {}'.format(type(obj).__name__, args_msg))
        raise DeserializationError(err_msg, obj, cls)

"""
    cls_ = None
    kwargs_ = {**kwargs}
    cls_args = get_args(cls)
    if cls_args:
        cls_ = cls_args[0]
        # Mark the cls as 'inferred' so that later it is known where cls came
        # from and the precedence of classes can be determined.
        kwargs_['_inferred_cls'] = True

    if tasks == 1:
        result = [load(elem, cls=cls_, tasks=1, **kwargs_) for elem in obj]
    elif tasks > 1:
        result = multi_task(load, obj, tasks, task_type, cls_, **kwargs_)
    else:
        raise JsonsError('Invalid number of tasks: {}'.format(tasks))
    return result

def _do_load(json_obj: object,
             deserializer: callable,
             cls: type,
             initial: bool,
             **kwargs):
    try:
        result = deserializer(json_obj, cls, **kwargs)
        validate(result, cls, kwargs['fork_inst'])
    except Exception as err:
        clear()
        if isinstance(err, JsonsError):
            raise
        raise DeserializationError(str(err), json_obj, cls)
    else:
        if initial:
            # Clear all lru caches right before returning the initial call.
            clear()
        return result

:param argument: the name of the argument in question.
        """
        JsonsError.__init__(self, message)
        ValueError.__init__(self, message)
        self._argument = argument

    @property
    def argument(self) -> str:
        """
        The argument in question.
        :return: the name of the argument.
        """
        return self._argument


class DeserializationError(JsonsError):
    """
    Raised when deserialization failed for some reason.
    """
    def __init__(self, message: str, source: object, target: Optional[type]):
        """
        Constructor.
        :param message: the message describing the problem.
        :param source: the object that was to be deserialized.
        :param target: the type to which `source` was to be deserialized.
        """
        JsonsError.__init__(self, message)
        self._source = source
        self._target = target

    @property
    def source(self) -> object:

"""
        The object that was to be deserialized.
        :return: the object that was to be deserialized.
        """
        return self._source

    @property
    def target(self) -> Optional[type]:
        """
        The target type to which `source` was to be deserialized.
        :return: the type to which `source` was to be deserialized.
        """
        return self._target


class SerializationError(JsonsError):
    """
    Raised when serialization failed for some reason.
    """


class RecursionDetectedError(SerializationError):
    """
    Raised when a recursive structure was detected and a stack overflow was
    prevented during serialization.
    """


class DecodeError(DeserializationError, JSONDecodeError):
    """
    Raised when decoding a string or bytes to Python types failed. This error
    is actually a wrapper around `json.JSONDecodeError`.

cls = get_cls_from_str(cls, json_obj, fork_inst)
    cls, meta_hints = _check_and_get_cls_and_meta_hints(
        json_obj, cls, fork_inst, kwargs.get('_inferred_cls', False))

    deserializer = _get_deserializer(cls, fork_inst)
    kwargs_ = {
        'strict': strict,
        'fork_inst': fork_inst,
        'attr_getters': attr_getters,
        'meta_hints': meta_hints,
        **kwargs
    }
    try:
        return deserializer(json_obj, cls, **kwargs_)
    except Exception as err:
        if isinstance(err, JsonsError):
            raise
        raise DeserializationError(str(err), json_obj, cls)

:param target_name: the name of the type that was the target type.
        """
        DeserializationError.__init__(self, message, source, None)
        self._target_name = target_name

    @property
    def target_name(self) -> str:
        """
        The name of the type that was unsuccessfully attempted to deserialize
        into.
        :return: the name of the type that was to be the target type.
        """
        return self._target_name


class InvalidDecorationError(JsonsError):
    """
    Raised when a jsons decorator was wrongly used.
    """
    def __init__(self, message: str):
        """
        Constructor.
        :param message: the message of this error.
        """
        JsonsError.__init__(self, message)

Base class for all `jsons` errors.
    """
    def __init__(self, message: str):
        """
        Constructor.
        :param message: the message describing the problem.
        """
        Exception.__init__(self, message)
        self._message = message

    @property
    def message(self):
        return self._message


class ValidationError(JsonsError):
    """
    Raised when the validation of an object failed.
    """


class ArgumentError(JsonsError, ValueError):
    """
    Raised when serialization or deserialization went wrong caused by a wrong
    argument when serializing or deserializing.
    """
    def __init__(self, message: str, argument: str):
        """
        Constructor.
        :param message: the message describing the problem.
        :param argument: the name of the argument in question.
        """

def default_union_deserializer(obj: object, cls: Union, **kwargs) -> object:
    """
    Deserialize an object to any matching type of the given union. The first
    successful deserialization is returned.
    :param obj: The object that needs deserializing.
    :param cls: The Union type with a generic (e.g. Union[str, int]).
    :param kwargs: Any keyword arguments that are passed through the
    deserialization process.
    :return: An object of the first type of the Union that could be
    deserialized successfully.
    """
    for sub_type in cls.__args__:
        try:
            return _main_impl.load(obj, sub_type, **kwargs)
        except JsonsError:
            pass  # Try the next one.
    else:
        args_msg = ', '.join([get_class_name(cls_) for cls_ in cls.__args__])
        err_msg = ('Could not match the object of type "{}" to any type of '
                   'the Union: {}'.format(str(cls), args_msg))
        raise DeserializationError(err_msg, obj, cls)