How to use the dataclasses._is_dataclass_instance function in dataclasses

def _asdict(obj, encode_json=False):
    """
    A re-implementation of `asdict` (based on the original in the `dataclasses`
    source) to support arbitrary Collection and Mapping types.
    """
    if _is_dataclass_instance(obj):
        result = []
        for field in fields(obj):
            value = _asdict(getattr(obj, field.name), encode_json=encode_json)
            result.append((field.name, value))
        return _encode_overrides(dict(result), _user_overrides(obj),
                                 encode_json=encode_json)
    elif isinstance(obj, Mapping):
        return dict((_asdict(k, encode_json=encode_json),
                     _asdict(v, encode_json=encode_json)) for k, v in
                    obj.items())
    elif isinstance(obj, Collection) and not isinstance(obj, str) and not isinstance(obj, bytes):
        return list(_asdict(v, encode_json=encode_json) for v in obj)
    else:
        return copy.deepcopy(obj)

def _asdict(obj, encode_json=False):
    """
    A re-implementation of `asdict` (based on the original in the `dataclasses`
    source) to support arbitrary Collection and Mapping types.
    """
    if _is_dataclass_instance(obj):
        result = []
        for field in fields(obj):
            value = _asdict(getattr(obj, field.name), encode_json=encode_json)
            result.append((field.name, value))

        result = _handle_undefined_parameters_safe(cls=obj, kvs=dict(result),
                                                   usage="to")
        return _encode_overrides(dict(result), _user_overrides(obj),
                                 encode_json=encode_json)
    elif isinstance(obj, Mapping):
        return dict((_asdict(k, encode_json=encode_json),
                     _asdict(v, encode_json=encode_json)) for k, v in
                    obj.items())
    elif isinstance(obj, Collection) and not isinstance(obj, str) \
            and not isinstance(obj, bytes):
        return list(_asdict(v, encode_json=encode_json) for v in obj)