@Test
	public void angleTest() {
		for (int i = 0; i < TESTS; i++) {
			double x1 = rand.nextInt();
			double y1 = rand.nextInt();
			Vector v1 = new Vector(x1, y1);
			Vector v2 = new Vector(-x1, -y1);
			assertEquals(v1.angle(), v2.angle().add(new Angle(180.0)));
		}
	}