assertTrue(plot1.equals(plot2));
// foreground range markers...
plot1.addRangeMarker(1, new ValueMarker(4.0), Layer.FOREGROUND);
assertFalse(plot1.equals(plot2));
plot2.addRangeMarker(1, new ValueMarker(4.0), Layer.FOREGROUND);
assertTrue(plot1.equals(plot2));
// background range markers...
plot1.addRangeMarker(1, new ValueMarker(5.0), Layer.BACKGROUND);
assertFalse(plot1.equals(plot2));