@Test
public void testScaleAdd() {

  final Vector2 vec1 = new Vector2(1, 1);
  final Vector2 vec2 = vec1.scaleAdd(2.0, new Vector2(1, 2), null);
  final Vector2 vec2B = vec1.scaleAdd(2.0, new Vector2(1, 2), new Vector2());
  assertEquals(new Vector2(3.0, 4.0), vec2);
  assertEquals(new Vector2(3.0, 4.0), vec2B);
  vec1.scaleAddLocal(2.0, new Vector2(1, 2));
  assertEquals(vec2, vec1);
}