$user = User::getKV('nickname', sprintf('%s%d', $userprefix, $n));
$group = User_group::register(array('nickname' => sprintf('%s%d', $groupprefix, $i),
$user = User::getKV('nickname', sprintf('%s%d', $userprefix, $n));
$group = User_group::register(array('nickname' => sprintf('%s%d', $groupprefix, $i),