def _get_instance_tag_cache(self, instance):
        return getattr(instance, '_%s_cache' % self.attname, None)
Test hook method that returns a package name for policy modules.
dataset/ETHPy150Open amarandon/smeuhsocial/apps/tagging/fields.py/TagField._get_instance_tag_cache--crossover with--dataset/ETHPy150Open Kuniwak/vint/vint/bootstrap.py/_get_policy_package_name_for_test