public function getDefaultRelation($class)
    {
        if ($defaultRelations = $this->config()->default_relations) {
            
            if (isset($defaultRelations[$class])) {
                
                $result = $this->processValue($defaultRelations[$class]);
                
                if ($result instanceof DataObject) {
                    return $result->ID;
                }
                
                return $result;
                
            }
            
        }
    }