docs: protected void printHeader(Graphics2D g2d, String headerText)
      {
          FontMetrics fm = g2d.getFontMetrics();
          int textHeight = fm.getHeight();
          int stringWidth = fm.stringWidth(headerText);
          int textX = (pageRect.width - stringWidth) / 2 + pageRect.x;
          int textY = pageRect.y + textHeight + BORDER;
          g2d.drawString(headerText , textX, textY);
      }