/**
  * helper function for sql string creation. change last_updated to updated
  *
  * @access private
  * @param object $obj
  * @param array $vars array of variables
  * @return array quoted strings
  */
 function &_makeVarsArray4SQL(&$obj, &$vars)
 {
     $ret = parent::_makeVarsArray4SQL($obj, $vars);
     $ret['updated'] = 'FROM_UNIXTIME(' . $ret['updated'] . ')';
     return $ret;
 }