[Dbix-class] Join the same table twice

[myshare]

I try to

$conn->search(
    { 'Conn_1.rid' => $tid, 'Conn_2.rid' => $pid, 'Conn_1.gid' =>
'Conn_2.gid' },
    {  join => [ 'Conn', 'Conn' ] }
 );

as mentioned in the Join-docs,
but get this error :

DBIx::Class::ResultSet::next(): No such relationship Conn ....

But I don't have to define any relation if it is using the same table, right ?

Second question : If I use auto loader, how can I still use the
autoloader, but add some modification to the classes ? thanx