!7 p { // This doesn't do anything (maybe it's too late?), you need to put it in the command line (-Djava.awt.headless=true). System.setProperty("java.awt.headless", "true"); print("Headless: " + isHeadless()); new CirclesAndLines cal; Circle a = cal.circle_autoVis("Yo", 0.2, 0.5); Circle b = cal.circle_autoVis("Yo-Yo", 0.8, 0.5); cal.arrow(a, "ARROW", b); BufferedImage img = cal.makeImage(600, 600); byte[] png = toPNG(img); print("PNG made. " + l(png) + " bytes"); }