prependDD(.3, .3);
prependDD(.4, Double.NaN);
prependDD(.5, Double.NaN);
CountingGraphics g = paint(new Rectangle(24, 176, 10, 10));
LineChecker c = new LineChecker();
c.require(19, 180, 39, 160);
c.allow(39, 160, 59, 140);
c.check(g.getLines());
assertEquals(g.getLines().size() + 1, g.getPointCount());
}