public function getZipData() {
        if (!$this->isFinalized) {
            $this->finalize();
        }
        if (!is_resource($this->zipFile)) {
            return $this->zipData;
        } else {
            rewind($this->zipFile);
            $filestat = fstat($this->zipFile);
            return fread($this->zipFile, $filestat['size']);
        }
    }