e.g.

```class SK_Paging_Conversation_UserOwner extends SK_Paging_Conversation_Abstract {

    function __construct(SK_User $user) {
        $source = new CM_PagingSource_MongoDB(array('messages' => 0), 'sk_conversation', array('userId' => $user->getId()));
        parent::__construct($source);
    }
}
```