@Test(expected = InvalidTransformException.class)
public void testSetRotationReadOnlyQuaternion() {

  final ValidatingTransform vt1 = new ValidatingTransform();
  final Quaternion rotation = new Quaternion();
  vt1.setRotation(rotation); // good
  rotation.setX(Double.NaN);
  vt1.setRotation(rotation); // bad
}