cb.setPatternFill(pat2, Color.blue);
cb.rectangle(200, 400, 30, 130);
cb.fillStroke();
cb.setPatternFill(pat2, new GrayColor(0.5f));
cb.rectangle(250, 400, 30, 80);
cb.fillStroke();
cb.setPatternFill(pat2, new GrayColor(0.7f));
cb.rectangle(300, 400, 30, 170);
cb.fillStroke();
cb.setPatternFill(pat2, new GrayColor(0.9f));
cb.rectangle(350, 400, 30, 40);