public void testIsEmpty() { assertFalse(r.isEmpty()); assertTrue(new Rectangle2D.Double(1, 2, -1, 1).isEmpty()); assertTrue(new Rectangle2D.Double(3, 4, 1, -1).isEmpty()); assertTrue(new Rectangle2D.Double(3, 4, 1, 0).isEmpty()); assertTrue(new Rectangle2D.Double(5, 6, -1, -1).isEmpty()); }