@Test
@Override
public void testStateChanged_ButNotAfterRemoval_RingSet() {

    ChemObjectListener listener = new ChemObjectListener();
    IChemModel chemObject = (IChemModel) newChemObject();
    chemObject.addListener(listener);
    IRingSet ringSet = chemObject.getBuilder().newInstance(IRingSet.class);
    chemObject.setRingSet(ringSet);
    Assert.assertFalse(listener.getChanged());
    // remove the set from the IChemModel
    chemObject.setRingSet(null);
    // reset the listener
    listener.reset();
    Assert.assertFalse(listener.getChanged());
    // changing the set must *not* trigger a change event in the IChemModel
    ringSet.addAtomContainer(chemObject.getBuilder().newInstance(IRing.class));
    Assert.assertFalse(listener.getChanged());
}