@Override
  protected void paintHorizontal(Graphics g, Dimension size) {
    for (int i = 0; i < SIZE; i++) {
      g.drawLine(0, i + SIZE, size.width, i + SIZE);
      g.drawLine(i, 0, i, FULL_SIZE);
      g.drawLine(size.width - i - 1, 0, size.width - i - 1, FULL_SIZE);
    }
  }
@Override
  protected void paintHorizontal(Graphics g, Dimension size)