public function __set($name, $value)
 {
     if (is_null($this->_prefix)) {
         return;
     }
     $pattern = '/^' . $this->_prefix . "/i";
     if (!preg_match($pattern, $name)) {
         $name = $this->_prefix . $name;
     }
     parent::__set($name, $value);
 }