}
}

func upper(s string) string {
	if s == "" {
		return ""
	}
	r, size := utf8.DecodeRuneInString(s)
	if r == '_' {
		return "X" + s
	}
	return string(unicode.ToUpper(r)) + s[size:]
}

// godefsFields rewrites field names for use in Go or C definitions.
// It strips leading common prefixes (like tv_ in tv_sec, tv_usec)

}

func TestToUpper(t *testing.T) { runStringTests(t, ToUpper, "ToUpper", upperTests) }

func TestToLower(t *testing.T) { runStringTests(t, ToLower, "ToLower", lowerTests) }

func BenchmarkToUpper(b *testing.B) {
	for _, tc := range upperTests {
		tin := []byte(tc.in)
		b.Run(tc.in, func(b *testing.B) {
			for i := 0; i < b.N; i++ {
				actual := ToUpper(tin)
				if !Equal(actual, tc.out) {