Void (Graphics2D g) { double[][] values = { {0, 0, 0, 0}, {Double.MAX_VALUE, Double.MAX_VALUE, Double.MAX_VALUE, Double.MAX_VALUE}, {-Double.MAX_VALUE, -Double.MAX_VALUE, -Double.MAX_VALUE, -Double.MAX_VALUE}, }; for (double[] v : values) paintBoundaries(g, v); return null; }