@Test
public void testGetAtomCount_IMolecularFormula() {

    IMolecularFormula formula = new MolecularFormula();
    formula.addIsotope(builder.newInstance(IIsotope.class, "C"));
    formula.addIsotope(builder.newInstance(IIsotope.class, "H"), 3);
    Assert.assertEquals(2, formula.getIsotopeCount());
    Assert.assertEquals(4, MolecularFormulaManipulator.getAtomCount(formula));
}