How to use the graphene-sqlalchemy.graphene_sqlalchemy.utils.is_mapped function in graphene-sqlalchemy

model=None,
            local_fields=None,
            only_fields=(),
            exclude_fields=(),
            id='id',
            interfaces=(),
            registry=None
        )

        if not options.registry:
            options.registry = get_global_registry()
        assert isinstance(options.registry, Registry), (
            'The attribute registry in {}.Meta needs to be an'
            ' instance of Registry, received "{}".'
        ).format(name, options.registry)
        assert is_mapped(options.model), (
            'You need to pass a valid SQLAlchemy Model in '
            '{}.Meta, received "{}".'
        ).format(name, options.model)


        cls = ObjectTypeMeta.__new__(cls, name, bases, dict(attrs, _meta=options))

        options.registry.register(cls)

        options.sqlalchemy_fields = yank_fields_from_attrs(
            construct_fields(options),
            _as=Field,
        )
        options.fields = merge(
            options.interface_fields,
            options.sqlalchemy_fields,

def is_type_of(cls, root, context, info):
        if isinstance(root, cls):
            return True
        if not is_mapped(type(root)):
            raise Exception((
                'Received incompatible instance "{}".'
            ).format(root))
        return type(root) == cls._meta.model