for i := 0; i < b.N; i++ {
					Trim(x[:k], cs[:j])
				}
			})
		}
	}
}

func BenchmarkTrimByte(b *testing.B) {
	x := []byte("  the quick brown fox   ")
	for i := 0; i < b.N; i++ {
		Trim(x, " ")
	}
}

func BenchmarkIndexPeriodic(b *testing.B) {
	key := []byte{1, 1}
	for _, skip := range [...]int{2, 4, 8, 16, 32, 64} {

	return nil
}

// WriteRune appends the UTF-8 encoding of Unicode code point r to the
// buffer, returning its length and an error, which is always nil but is
// included to match [bufio.Writer]'s WriteRune. The buffer is grown as needed;
// if it becomes too large, WriteRune will panic with [ErrTooLarge].
func (b *Buffer) WriteRune(r rune) (n int, err error) {
	// Compare as uint32 to correctly handle negative runes.
	if uint32(r) < utf8.RuneSelf {

func (r panicReader) Read(p []byte) (int, error) {
	if r.panic {
		panic("oops")
	}
	return 0, io.EOF
}

// Make sure that an empty Buffer remains empty when
// it is "grown" before a Read that panics
func TestReadFromPanicReader(t *testing.T) {

	// First verify non-panic behaviour
	var buf Buffer
	i, err := buf.ReadFrom(panicReader{})
	if err != nil {
		t.Fatal(err)
	}