public function write($output)
    {
        //lets parse the file
        if ($this->_hasBeenModified($this->_file) || !file_exists($output)) {
            //get the data
            file_put_contents($output, $this->getData());
            //update the timestamp
            $this->_cache_data['timestamp'] = time();
            file_put_contents($this->_cache_file, serialize($this->_cache_data));
        }
    }