@Test
public void testScaleAdd() {

  final Vector4 vec1 = new Vector4(1, 1, 1, 1);
  final Vector4 vec2 = vec1.scaleAdd(2.0, new Vector4(1, 2, 3, 4), null);
  final Vector4 vec2B = vec1.scaleAdd(2.0, new Vector4(1, 2, 3, 4), new Vector4());
  assertEquals(new Vector4(3.0, 4.0, 5.0, 6.0), vec2);
  assertEquals(new Vector4(3.0, 4.0, 5.0, 6.0), vec2B);
  vec1.scaleAddLocal(2.0, new Vector4(1, 2, 3, 4));
  assertEquals(vec2, vec1);
}