var spd sparseDatas
	var spb []byte
	blk := tw.templateV7Plus(hdr, f.formatString, f.formatNumeric)
	if !hdr.AccessTime.IsZero() {
		f.formatNumeric(blk.toGNU().accessTime(), hdr.AccessTime.Unix())
	}
	if !hdr.ChangeTime.IsZero() {
		f.formatNumeric(blk.toGNU().changeTime(), hdr.ChangeTime.Unix())
	}
	// TODO(dsnet): Re-enable this when adding sparse support.
	// See https://golang.org/issue/22735
	/*

		}
		if v, ok := h.PAXRecords[paxKey]; ok && v == formatPAXTime(ts) {
			paxHdrs[paxKey] = v
		}
	}

	// Check basic fields.
	var blk block
	v7 := blk.toV7()
	ustar := blk.toUSTAR()
	gnu := blk.toGNU()
	verifyString(h.Name, len(v7.name()), "Name", paxPath)
	verifyString(h.Linkname, len(v7.linkName()), "Linkname", paxLinkpath)
	verifyString(h.Uname, len(ustar.userName()), "Uname", paxUname)

			copy(sa.isExtended(), "\x80")
		}
		return sps
	}

	makeInput := func(format Format, size string, sps ...string) (out []byte) {
		// Write the initial GNU header.
		var blk block
		gnu := blk.toGNU()
		sparse := gnu.sparse()
		copy(gnu.realSize(), size)
		sps = populateSparseMap(sparse, sps)
		if format != FormatUnknown {
			blk.setFormat(format)
		}
		out = append(out, blk[:]...)