@Test
public void testGetIsotopes_IMolecularFormula_IElement() {

    IMolecularFormula formula = new MolecularFormula();
    IIsotope carb = builder.newInstance(IIsotope.class, "C");
    IIsotope flu = builder.newInstance(IIsotope.class, "F");
    IIsotope h1 = builder.newInstance(IIsotope.class, "H");
    IIsotope h2 = builder.newInstance(IIsotope.class, "H");
    h2.setExactMass(2.014101778);
    formula.addIsotope(carb, 1);
    formula.addIsotope(flu);
    formula.addIsotope(h1, 1);
    formula.addIsotope(h2, 2);
    List<IIsotope> isotopes = MolecularFormulaManipulator.getIsotopes(formula,
            builder.newInstance(IElement.class, "H"));
    Assert.assertEquals(2, isotopes.size());
}