public function __construct()
 {
     $params = func_get_args();
     if (count($params) < 1) {
         throw new CException('Invalid arguments count passed to c-tor of' . __CLASS__ . '!');
     }
     // Cast all params to string values
     //        foreach($params as $idx => $param)
     //            if(!is_string($param))
     //                $params[$idx] = (string)$param;
     parent::__construct($this->getConcatExpression(), $params);
 }
 public function __construct($toLower)
 {
     $this->_toLower = $toLower;
     parent::__construct($this->generateExpression());
 }