br := NewReader(strings.NewReader("example"))
	br.WriteTo(io.Discard)
	if err := br.UnreadRune(); err == nil {
		t.Error("UnreadRune didn't fail after WriteTo")
	}
}

func TestNoUnreadByteAfterWriteTo(t *testing.T) {
	br := NewReader(strings.NewReader("example"))
	br.WriteTo(io.Discard)
	if err := br.UnreadByte(); err == nil {
		t.Error("UnreadByte didn't fail after WriteTo")
	}
}