def _ban_time_left(self, value):
        return (time.time() - (value.time + self.bantime.total_seconds()))
If `allow_null=True` then `None` is a valid input.
dataset/ETHPy150Open biicode/bii-server/rest/bottle_plugins/generic_blocker_bottle_plugin.py/GenericBlockerBottlePlugin._ban_time_left--crossover with--dataset/ETHPy150Open tomchristie/django-rest-framework/tests/test_fields.py/TestEmpty.test_allow_null