Get the list of parent items for this view.
        This must be an iterable, and may be a queryset.
        Defaults to using `self.parent_queryset`.
        You may want to override this if you need to provide different
        querysets depending on the incoming request.
        (Eg. return a list of items that is specific to the user)

def get_parent_queryset(self):
        """
        Get the list of parent items for this view.
        This must be an iterable, and may be a queryset.
        Defaults to using `self.parent_queryset`.
        You may want to override this if you need to provide different
        querysets depending on the incoming request.
        (Eg. return a list of items that is specific to the user)
        """
        if self.parent_queryset is not None:
            return self.parent_queryset._clone()

        if self.parent_model is not None:
            return self.parent_model._default_manager.all()

        raise ImproperlyConfigured(
            "'%s' must define 'parent_queryset' or "
            "'parent_model'" % self.__class__.__name__
        )