@Test
public void testCarbons() throws Exception {

    IsotopeFactory ifac = Isotopes.getInstance();
    IIsotope c = ifac.getMajorIsotope("C");
    MolecularFormulaRange mfRange = new MolecularFormulaRange();
    mfRange.addIsotope(c, 0, 100000);
    double minMass = 120000.0 - 1;
    double maxMass = 120000.0 + 1;
    MolecularFormulaGenerator gen = new MolecularFormulaGenerator(builder,
            minMass, maxMass, mfRange);
    IMolecularFormulaSet mfSet = gen.getAllFormulas();
    Assert.assertNotNull(mfSet);
    Assert.assertEquals(1, mfSet.size());
    Assert.assertEquals("C10000", MolecularFormulaManipulator
            .getString(mfSet.getMolecularFormula(0)));
}