/**
  * @access private
  */
 public function store()
 {
     parent::store();
     if (isset($this->_old_file_name) && file_exists($this->_old_file_name)) {
         @unlink($this->_old_file_name);
         @unlink($this->thumbnail_file_name($this->_old_file_name));
     }
 }