@Test
public void testGetString_IMolecularFormula_boolean() {

    IMolecularFormula mf1 = new MolecularFormula();
    mf1.addIsotope(builder.newInstance(IIsotope.class, "C"), 1);
    mf1.addIsotope(builder.newInstance(IIsotope.class, "H"), 4);
    Assert.assertEquals("C1H4", MolecularFormulaManipulator.getString(mf1, true));
}