r.ReadRune()
	r.UnreadRune()
	_, _, err := r.ReadRune()
	if err == nil {
		t.Error("expected error at EOF")
	} else if err != io.EOF {
		t.Error("expected EOF; got", err)
	}
}

func TestReadWriteRune(t *testing.T) {
	const NRune = 1000
	byteBuf := new(bytes.Buffer)
	w := NewWriter(byteBuf)
	// Write the runes out using WriteRune
	buf := make([]byte, utf8.UTFMax)
	for r := rune(0); r < NRune; r++ {