def save_prep(cls, instance_or_instances):
        """Preprocess the object before the object is saved.  This
        automatically gets called when the save method gets called.
        """
        instances = make_obj_list(instance_or_instances)

        tokens = set(cls.objects.get_available_tokens(
            count=len(instances),
            token_length=cls.token_length
        ))

        for instance in instances:
            if not instance.token:
                instance.token = tokens.pop()

        super(AbstractTokenModel, cls).save_prep(
            instance_or_instances=instances
        )
Preprocess the object before the object is saved.  This
        automatically gets called when the save method gets called.