var sz int64
	f, e := os.Open(downloadPath)
	if e != nil {
		return e
	}
	if st, e := f.Stat(); e == nil {
		sz = st.Size()
	}
	defer f.Close()
	r = f

	zr, e := zip.NewReader(r.(io.ReaderAt), sz)
	if e != nil {
		return e
	}
	for _, file := range zr.File {
		if !file.FileInfo().IsDir() && strings.HasSuffix(file.Name, "xl.meta") {
			r, e := file.Open()
			if e != nil {
				return e
			}