@Test
public void testPetitjeanNumberDescriptor() throws java.lang.Exception {

    SmilesParser sp = new SmilesParser(DefaultChemObjectBuilder.getInstance());
    IAtomContainer mol = sp.parseSmiles("O=C(O)CC");
    AtomContainerManipulator.removeHydrogens(mol);
    Assert.assertEquals(0.33333334, ((DoubleResult) descriptor.calculate(mol).getValue()).doubleValue(), 0.01);
}