for k := range paxHdrs {
			keys = append(keys, k)
		}
		sort.Strings(keys)

		// Write each record to a buffer.
		var buf strings.Builder
		for _, k := range keys {
			rec, err := formatPAXRecord(k, paxHdrs[k])
			if err != nil {
				return err
			}
			buf.WriteString(rec)
		}

		// Write the extended header file.
		var name string
		var flag byte
		if isGlobal {