+ g.setColor(Color.WHITE);
+ g.setStroke(new BasicStroke(stroke_width+4, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND));
+ g.draw(line);
+
+ g.setColor(Color.BLUE);
+ g.setStroke(new BasicStroke(stroke_width, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND));