@Test
public void testTwoVersusDoubleBondedOxygen() throws Exception {

    IAtomContainer molecule = smiles.parseSmiles("OC(O)C([H])(C)C=O");
    ILigand ligand1 = CIPTool.defineLigand(molecule, new VisitedAtoms(), 3, 1);
    ILigand ligand2 = CIPTool.defineLigand(molecule, new VisitedAtoms(), 3, 6);
    ISequenceSubRule<ILigand> rule = new CIPLigandRule();
    Assert.assertEquals(-1, rule.compare(ligand1, ligand2));
    Assert.assertEquals(1, rule.compare(ligand2, ligand1));
}