for n, test := range scanTests {
		buf := strings.NewReader(test)
		s := NewScanner(buf)
		s.Split(ScanRunes)
		var i, runeCount int
		var expect rune
		// Use a string range loop to validate the sequence of runes.
		for i, expect = range test {
			if !s.Scan() {
				break
			}
			runeCount++
			got, _ := utf8.DecodeRune(s.Bytes())
			if got != expect {
				t.Errorf("#%d: %d: expected %q got %q", n, i, expect, got)
			}

	for _, row := range output {
		for i, col := range row {
			_, _ = fmt.Fprint(c.writer, col.String())
			if i == len(row)-1 {
				_, _ = fmt.Fprint(c.writer, "\n")
			} else {
				padAmount := sep[i] - utf8.RuneCount([]byte(col.Value)) + 2
				_, _ = fmt.Fprint(c.writer, strings.Repeat(" ", padAmount))
			}
		}
	}
}

func max(x, y int) int {
	if x < y {
		return y
	}
	return x
}

// If sep is an empty slice, Count returns 1 + the number of UTF-8-encoded code points in s.
func Count(s, sep []byte) int {
	// special case
	if len(sep) == 0 {
		return utf8.RuneCount(s) + 1
	}
	if len(sep) == 1 {
		return bytealg.Count(s, sep[0])
	}
	n := 0
	for {
		i := Index(s, sep)
		if i == -1 {
			return n
		}
		n++
		s = s[i+len(sep):]
	}
}

pkg unicode/utf8, func EncodeRune([]uint8, int32) int
pkg unicode/utf8, func FullRune([]uint8) bool
pkg unicode/utf8, func FullRuneInString(string) bool
pkg unicode/utf8, func RuneCount([]uint8) int
pkg unicode/utf8, func RuneCountInString(string) int
pkg unicode/utf8, func RuneLen(int32) int
pkg unicode/utf8, func RuneStart(uint8) bool
pkg unicode/utf8, func Valid([]uint8) bool