def _get_instance_tag_cache(self, instance):
        return getattr(instance, '_%s_cache' % self.attname, None)
This handler is used for testing purposes and is explosive.
dataset/ETHPy150Open hzlf/openbroadcast/website/tagging_ng/fields.py/TagField._get_instance_tag_cache--crossover with--dataset/ETHPy150Open hfaran/Tornado-JSON/tests/func_test.py/ExplodingHandler.post