def _modified(time, prev, curr, collected):
    prev_dict = dict((res['id'], res) for res in prev)
    curr_dict = dict((res['id'], res) for res in curr)
    same = set(prev_dict.keys()) & set(curr_dict.keys())
    for id_val in same:
        if curr_dict[id_val] is not prev_dict[id_val]:
            m = dict((k, v)
                     for k, v in six.iteritems(prev_dict[id_val])
                     if v != curr_dict[id_val].get(k))
            m['time'] = time.isoformat()
            m['id'] = id_val
            collected.append(m)
    return collected
dataset/ETHPy150Open openstack/fuel-web/nailgun/nailgun/statistics/oswl/saver.py/_modified/operator `!=` -> `is not`