if (paint == null) {
            paint = CategoryPlot.DEFAULT_GRIDLINE_PAINT;
        }
        g2.setPaint(paint);

        Stroke stroke = plot.getDomainGridlineStroke();
        if (stroke == null) {
            stroke = CategoryPlot.DEFAULT_GRIDLINE_STROKE;
        }
        g2.setStroke(stroke);

        g2.draw(line);