def remove_old(self):
        stale_pulse = future_pulse(instance_preserve_hours * 60 * 60)
        for instance_id, instance in instance_map.copy().items():
            if stale_pulse < instance.pulse_stamp and not [entity for entity in instance.entities
                                                           if hasattr(entity, 'is_player') and entity.session]:
                del instance_map[instance_id]
dataset/ETHPy150Open genzgd/Lampost-Mud/lampost/env/instance.py/InstanceManager.remove_old/swapped operands of `<`