}
}

func TestUnreadRune(t *testing.T) {
	segments := []string{"Hello, world:", "日本語"}
	r := NewReader(&StringReader{data: segments})
	got := ""
	want := strings.Join(segments, "")
	// Normal execution.
	for {
		r1, _, err := r.ReadRune()
		if err != nil {
			if err != io.EOF {
				t.Error("unexpected error on ReadRune:", err)
			}
			break
		}
		got += string(r1)