Phalcon关系不起作用

I trying to create hasMany relation in Phalcon PHP framework. Just as in a manual.

class TorrentSet extends \Phalcon\Mvc\Model
{
    public function initialize()
    {
        $this->hasMany(
            "id",
            "TorrentSetItem",
            "set_id"
        );
    }
}

class TorrentSetItem extends \Phalcon\Mvc\Model
{
    public function initialize()
    {
        $this->belongsTo('set_id', 'TorrentSet', 'id',
            array('alias' => 'set')
        );
    }

}

When I try to get related records:

$set = TorrentSet::findFirstById(1);

var_dump($set->torrentSetItem); 

And the result is always NULL, inspite of the presense records in DB:

mysql> select * from torrent_set where id = 1;
+----+------------+
| id | title      |
+----+------------+
|  1 | Film       |
+----+------------+
1 row in set (0.00 sec)

mysql> select * from torrent_set_item where set_id = 1;
+----+--------+---------+-----+
| id | set_id | attr_id | pos |
+----+--------+---------+-----+
|  1 |      1 |       2 |   0 |
|  2 |      1 |       1 |   1 |
+----+--------+---------+-----+
2 rows in set (0.01 sec)

Seems it was just a Browser cache. All works fine. And I should set the full path to model: Apt\Models\TorrentSetItem instead of TorrentSetItem