public function changeConfigTable($definition)
 {
     try {
         $change = new SimpleXMLElement($definition);
         $operation = $change->operation;
         $operation = trim($operation . "");
         switch ($operation) {
             case 'UPDATE':
                 $key = trim($change->key . "");
                 $value = trim($change->value . "");
                 $result = $this->_setConfigValue($key, $value);
                 break;
             case 'ADD':
                 $key = trim($change->key . "");
                 $value = trim($change->value . "");
                 $config = new Config();
                 $config->setProperty($key);
                 $config->setValue($value);
                 $config->save();
             default:
         }
     } catch (Exception $exc) {
         echo $exc->getTraceAsString();
     }
 }