whmcsDNSManager/modules/addons/DNSManager2/models/whmcs/clients/repository.php

<?php

namespace MGModule\DNSManager2\models\whmcs\clients;
use MGModule\DNSManager2 as main;

/**
 * Description of repository
 */
class repository extends \MGModule\DNSManager2\mgLibs\models\repository{
    public function getModelClass() {
        return __NAMESPACE__.'\client';
    }
}