// headers since 0.0 headers were not PAX compliant.
	var sparseMap []string

	paxHdrs := make(map[string]string)
	for len(sbuf) > 0 {
		key, value, residual, err := parsePAXRecord(sbuf)
		if err != nil {
			return nil, ErrHeader
		}
		sbuf = residual

		switch key {
		case paxGNUSparseOffset, paxGNUSparseNumBytes:
			// Validate sparse header order and value.