How to use the jsons._common_impl.StateHolder function in jsons

def test_get_offset_str(self):
        dat = datetime.datetime(year=2018, month=7, day=8, hour=21, minute=34,
                                tzinfo=datetime.timezone.utc)

        td = datetime.timedelta(hours=3)

        dat2 = datetime.datetime(year=2018, month=7, day=8, hour=21, minute=34,
                                tzinfo=datetime.timezone(td))

        offset_str_dat = get_offset_str(dat, StateHolder)
        offset_str_dat2 = get_offset_str(dat2, StateHolder)
        offset_str_td = get_offset_str(td, StateHolder)

        self.assertEqual('Z', offset_str_dat)
        self.assertEqual('+03:00', offset_str_dat2)
        self.assertEqual('+03:00', offset_str_td)

def announce_class(
        cls: type,
        cls_name: Optional[str] = None,
        fork_inst: type = StateHolder):
    """
    Announce the given cls to jsons to allow jsons to deserialize a verbose
    dump into that class.
    :param cls: the class that is to be announced.
    :param cls_name: a custom name for that class.
    :param fork_inst: if given, it uses this fork of ``JsonSerializable``.
    :return: None.
    """
    cls_name = cls_name or get_class_name(cls, fully_qualified=True)
    fork_inst._announced_classes[cls] = cls_name
    fork_inst._announced_classes[cls_name] = cls

def set_serializer(
        func: callable,
        cls: Union[type, Sequence[type]],
        high_prio: bool = True,
        fork_inst: type = StateHolder) -> None:
    """
    Set a serializer function for the given type. You may override the default
    behavior of ``jsons.load`` by setting a custom serializer.

    The ``func`` argument must take one argument (i.e. the object that is to be
    serialized) and also a ``kwargs`` parameter. For example:

    >>> def func(obj, **kwargs):
    ...    return dict()

    You may ask additional arguments between ``cls`` and ``kwargs``.

    :param func: the serializer function.
    :param cls: the type or sequence of types this serializer can handle.
    :param high_prio: determines the order in which is looked for the callable.
    :param fork_inst: if given, it uses this fork of ``JsonSerializable``.

def get_class_name(cls: type,
                   transformer: Optional[Callable[[str], str]] = None,
                   fully_qualified: bool = False,
                   fork_inst: Optional[type] = StateHolder) -> Optional[str]:
    """
    Return the name of a class.
    :param cls: the class of which the name if to be returned.
    :param transformer: any string transformer, e.g. ``str.lower``.
    :param fully_qualified: if ``True`` return the fully qualified name (i.e.
    complete with module name).
    :param fork_inst if given, it uses this fork of ``JsonSerializable`` for
    finding the class name.
    :return: the name of ``cls``, transformed if a transformer is given.
    """
    transformer = transformer or (lambda x: x)
    cls_name = _get_special_cases(cls)
    if cls_name:
        return transformer(cls_name)
    if cls in fork_inst._announced_classes:
        return transformer(fork_inst._announced_classes[cls])

def get_serializer(
        cls: type,
        fork_inst: Optional[type] = StateHolder) -> callable:
    """
    Return the serializer function that would be used for the given ``cls``.
    :param cls: the type for which a serializer is to be returned.
    :param fork_inst: if given, it uses this fork of ``JsonSerializable``.
    :return: a serializer function.
    """
    serializer = _get_lizer(cls, fork_inst._serializers,
                            fork_inst._classes_serializers, fork_inst)
    return serializer

def dump(obj: object,
         cls: Optional[type] = None,
         fork_inst: Optional[type] = StateHolder,
         **kwargs) -> object:
    """
    Serialize the given ``obj`` to a JSON equivalent type (e.g. dict, list,
    int, ...).

    The way objects are serialized can be finetuned by setting serializer
    functions for the specific type using ``set_serializer``.

    You can also provide ``cls`` to specify that ``obj`` needs to be serialized
    as if it was of type ``cls`` (meaning to only take into account attributes
    from ``cls``). The type ``cls`` must have a ``__slots__`` defined. Any type
    will do, but in most cases you may want ``cls`` to be a base class of
    ``obj``.
    :param obj: a Python instance of any sort.
    :param cls: if given, ``obj`` will be dumped as if it is of type ``type``.
    :param fork_inst: if given, it uses this fork of ``JsonSerializable``.

from typing import Optional
from jsons._common_impl import get_class_name, StateHolder
from jsons._dump_impl import dump, dumps, dumpb
from jsons._lizers_impl import set_serializer, set_deserializer
from jsons._load_impl import load, loads, loadb


class JsonSerializable(StateHolder):
    """
    This class offers an alternative to using the ``jsons.load`` and
    ``jsons.dump`` methods. An instance of a class that inherits from
    ``JsonSerializable`` has the ``json`` property, which value is equivalent
    to calling ``jsons.dump`` on that instance. Furthermore, you can call
    ``from_json`` on that class, which is equivalent to calling ``json.load``
    with that class as an argument.
    """
    _fork_counter = 0

    @classmethod
    def fork(cls, name: Optional[str] = None) -> type:
        """
        Create a 'fork' of ``JsonSerializable``: a new ``type`` with a separate
        configuration of serializers and deserializers.
        :param name: the ``__name__`` of the new ``type``.

def suppress_warnings(
        do_suppress: Optional[bool] = True,
        fork_inst: Optional[type] = StateHolder):
    """
    Suppress (or stop suppressing) warnings.
    :param do_suppress: if ``True``, warnings will be suppressed from now on.
    :param fork_inst: if given, it uses this fork of ``JsonSerializable``.
    :return: None.
    """
    fork_inst._suppress_warnings = do_suppress

def default_object_serializer(
        obj: object,
        cls: Optional[type] = None,
        *,
        key_transformer: Optional[Callable[[str], str]] = None,
        strip_nulls: bool = False,
        strip_privates: bool = False,
        strip_properties: bool = False,
        strip_class_variables: bool = False,
        strip_attr: Union[str, MutableSequence[str], Tuple[str]] = None,
        verbose: Union[Verbosity, bool] = False,
        strict: bool = False,
        fork_inst: Optional[type] = StateHolder,
        **kwargs) -> Optional[dict]:
    """
    Serialize the given ``obj`` to a dict. All values within ``obj`` are also
    serialized. If ``key_transformer`` is given, it will be used to transform
    the casing (e.g. snake_case) to a different format (e.g. camelCase).
    :param obj: the object that is to be serialized.
    :param cls: the type of the object that is to be dumped.
    :param key_transformer: a function that will be applied to all keys in the
    resulting dict.
    :param strip_nulls: if ``True`` the resulting dict will not contain null
    values.
    :param strip_privates: if ``True`` the resulting dict will not contain
    private attributes (i.e. attributes that start with an underscore).
    :param strip_properties: if ``True`` the resulting dict will not contain
    values from @properties.
    :param strip_class_variables: if ``True`` the resulting dict will not

def validate(
        obj: object,
        cls: type,
        fork_inst: type = StateHolder) -> None:
    """
    Validate the given ``obj`` with the validator that was registered for
    ``cls``. Raises a ``ValidationError`` if the validation failed.
    :param obj: the object that is to be validated.
    :param cls: the type of which the validator function was registered.
    :param fork_inst: if given, it uses this fork of ``JsonSerializable``.
    :return: None.
    """
    validator = get_validator(cls, fork_inst)
    result = True
    msg = 'Validation failed.'
    if validator:
        try:
            result = validator(obj)
        except Exception as err:
            if err.args: