var buf Buffer
	s := ""
	for i := 0; i < 50; i++ {
		wlen := rand.Intn(len(testString))
		if i%2 == 0 {
			s = fillString(t, "TestMixedReadsAndWrites (1)", &buf, s, 1, testString[0:wlen])
		} else {
			s = fillBytes(t, "TestMixedReadsAndWrites (1)", &buf, s, 1, testBytes[0:wlen])
		}

		rlen := rand.Intn(len(testString))
		fub := make([]byte, rlen)
		n, _ := buf.Read(fub)
		s = s[n:]
	}

pkg math/rand/v2, func Int32() int32 #61716
pkg math/rand/v2, func Int32N(int32) int32 #61716
pkg math/rand/v2, func Int64() int64 #61716
pkg math/rand/v2, func Int64N(int64) int64 #61716
pkg math/rand/v2, func IntN(int) int #61716
pkg math/rand/v2, func N[$0 intType]($0) $0 #61716
pkg math/rand/v2, func New(Source) *Rand #61716
pkg math/rand/v2, func NewChaCha8([32]uint8) *ChaCha8 #61716

		}
	}
}

var makeFieldsInput = func() []byte {
	x := make([]byte, 1<<20)
	// Input is ~10% space, ~10% 2-byte UTF-8, rest ASCII non-space.
	for i := range x {
		switch rand.Intn(10) {
		case 0:
			x[i] = ' '
		case 1:
			if i > 0 && x[i-1] == 'x' {
				copy(x[i-1:], "χ")
				break
			}
			fallthrough
		default:
			x[i] = 'x'
		}
	}
	return x