if (orientation == PlotOrientation.VERTICAL) {
                    line = new Line2D.Double(xx0, yy, xx1, yy);
                    cap1 = new Line2D.Double(xx0, yy - adj, xx0, yy + adj);
                    cap2 = new Line2D.Double(xx1, yy - adj, xx1, yy + adj);
                }
                else {  // PlotOrientation.HORIZONTAL
                    line = new Line2D.Double(yy, xx0, yy, xx1);
                    cap1 = new Line2D.Double(yy - adj, xx0, yy + adj, xx0);
                    cap2 = new Line2D.Double(yy - adj, xx1, yy + adj, xx1);