var buf strings.Builder
	w := NewWriter(bufio.NewWriter(&buf))
	err := w.PrintfLine("foo %d", 123)
	if s := buf.String(); s != "foo 123\r\n" || err != nil {
		t.Fatalf("s=%q; err=%s", s, err)
	}
}

func TestDotWriter(t *testing.T) {
	var buf strings.Builder
	w := NewWriter(bufio.NewWriter(&buf))
	d := w.DotWriter()
	n, err := d.Write([]byte("abc\n.def\n..ghi\n.jkl\n."))
	if n != 21 || err != nil {