@Test
public void testFrontFacing() {

  final Plane plane = new Plane(new Vector3(0.0f, 0.1f, 0.2f), 0.3f);
  Assert.assertEquals(false, plane.isFrontFacing(new Vector3(0.4f, 0.5f, 0.6f)));
  Assert.assertEquals(true, plane.isFrontFacing(new Vector3(0.0f, 0.0f, 0.0f)));
}