public function overwrite($filepath)
    {
        $result = $this->sendOverwrite($filepath,
            $this->handle, $this->api_key, $this->security);

        // update metadata
        $this->metadata['filename'] = $result->metadata['filename'];
        $this->metadata['mimetype'] = $result->metadata['mimetype'];
        $this->metadata['size'] = $result->metadata['size'];

        return true;
    }