@Test
public void testAtAt() throws Exception {

    SmilesParser sp = new SmilesParser(DefaultChemObjectBuilder.getInstance());
    IAtomContainer mol = sp.parseSmiles("Br[C@@H](Cl)I");
    Iterator<IStereoElement> stereoElements = mol.stereoElements().iterator();
    assertTrue(stereoElements.hasNext());
    IStereoElement stereoElement = stereoElements.next();
    Assert.assertNotNull(stereoElement);
    assertTrue(stereoElement instanceof ITetrahedralChirality);
    ITetrahedralChirality l4Chiral = (ITetrahedralChirality) stereoElement;
    Assert.assertEquals("C", l4Chiral.getChiralAtom().getSymbol());
    IAtom[] ligands = l4Chiral.getLigands();
    for (IAtom atom : ligands)
        Assert.assertNotNull(atom);
    // note: the tetrahedral centre holds atom '1' to refer to implicit
    // hydrogen
    Assert.assertEquals(mol.getAtom(0), ligands[0]);
    Assert.assertEquals(mol.getAtom(1), ligands[1]);
    Assert.assertEquals(mol.getAtom(2), ligands[2]);
    Assert.assertEquals(mol.getAtom(3), ligands[3]);
    Assert.assertEquals(Stereo.CLOCKWISE, l4Chiral.getStereo());
}