{math.MaxInt64, "\x80\x7f\xff\xff\xff\xff\xff\xff\xff", true},
		{math.MinInt64, "\xff\x80\x00\x00\x00\x00\x00\x00\x00", true},
	}

	for _, v := range vectors {
		var f formatter
		got := make([]byte, len(v.want))
		f.formatNumeric(got, v.in)
		ok := (f.err == nil)
		if ok != v.ok {
			if v.ok {
				t.Errorf("formatNumeric(%d): got formatting failure, want success", v.in)
			} else {

	for _, c := range s {
		if c < 0x80 && c != 0x00 {
			b = append(b, byte(c))
		}
	}
	return string(b)
}

type parser struct {
	err error // Last error seen
}

type formatter struct {
	err error // Last error seen
}

// parseString parses bytes as a NUL-terminated C-style string.
// If a NUL byte is not found then the whole slice is returned as a string.

		copy(b.toUSTAR().version(), versionUSTAR)
	default:
		panic("invalid format")
	}

	// Update checksum.
	// This field is special in that it is terminated by a NULL then space.
	var f formatter
	field := b.toV7().chksum()
	chksum, _ := b.computeChecksum() // Possible values are 256..128776
	f.formatOctal(field[:7], chksum) // Never fails since 128776 < 262143
	field[7] = ' '
}

			var blk block
			sps = populateSparseMap(blk.toSparse(), sps)
			out = append(out, blk[:]...)
		}
		return out
	}

	makeSparseStrings := func(sp []sparseEntry) (out []string) {
		var f formatter
		for _, s := range sp {
			var b [24]byte
			f.formatNumeric(b[:12], s.Offset)
			f.formatNumeric(b[12:], s.Length)
			out = append(out, string(b[:]))
		}
		return out
	}

)

// templateV7Plus fills out the V7 fields of a block using values from hdr.
// It also fills out fields (uname, gname, devmajor, devminor) that are
// shared in the USTAR, PAX, and GNU formats using the provided formatters.
//
// The block returned is only valid until the next call to
// templateV7Plus or writeRawFile.
func (tw *Writer) templateV7Plus(hdr *Header, fmtStr stringFormatter, fmtNum numberFormatter) *block {
	tw.blk.reset()

pkg fmt, func Sscan(string, ...interface{}) (int, error)
pkg fmt, func Sscanf(string, string, ...interface{}) (int, error)
pkg fmt, func Sscanln(string, ...interface{}) (int, error)
pkg fmt, type Formatter interface { Format }
pkg fmt, type Formatter interface, Format(State, int32)
pkg fmt, type GoStringer interface { GoString }
pkg fmt, type GoStringer interface, GoString() string