/**
  * 
  */
 public function removeACLUserGroups($pa_group_ids)
 {
     if (!($vn_id = (int) $this->getPrimaryKey())) {
         return null;
     }
     require_once __CA_MODELS_DIR__ . '/ca_acl.php';
     $vn_table_num = $this->tableNum();
     $va_current_groups = $this->getUserGroups();
     $t_acl = new ca_acl();
     foreach ($pa_group_ids as $vn_group_id) {
         if (!isset($va_current_groups[$vn_group_id]) && $va_current_groups[$vn_group_id]) {
             continue;
         }
         $t_acl->setMode(ACCESS_WRITE);
         if ($t_acl->load(array('table_num' => $vn_table_num, 'row_id' => $vn_id, 'group_id' => $vn_group_id))) {
             $t_acl->delete(true);
             if ($t_acl->numErrors()) {
                 $this->errors = $t_acl->errors;
                 return false;
             }
         }
     }
     return true;
 }