docs: @Override
      protected void plotSymbol() {
  
          // hexagons
          for (int row = 0; row < 33; row++) {
              for (int col = 0; col < 30; col++) {
                  if (grid[row][col]) {
                      double x = (2.46 * col) + 1.23;
                      if ((row & 1) != 0) {
                          x += 1.23;
                      }
                      double y = (2.135 * row) + 1.43;
                      hexagons.add(new Hexagon(x, y));
                  }
              }
          }
  
          // circles
          double[] radii = { 10.85, 8.97, 7.10, 5.22, 3.31, 1.43 };
          for (int i = 0; i < radii.length; i++) {
              Ellipse2D.Double circle = new Ellipse2D.Double();
              circle.setFrameFromCenter(35.76, 35.60, 35.76 + radii[i], 35.60 + radii[i]);
              target.add(circle);
          }
      }