def _added(time, prev, curr, collected):
    prev_ids = set(res['id'] for res in prev)
    curr_ids = set(res['id'] for res in curr)
    added_ids = curr_ids / prev_ids
    for id_val in added_ids:
        collected.append({'id': id_val, 'time': time.isoformat()})
    return collected
dataset/ETHPy150Open openstack/fuel-web/nailgun/nailgun/statistics/oswl/saver.py/_added/operator `-` -> `/`