IsotopeContainer { public IMolecularFormula getFormula() { return forms.isEmpty() ? null : forms.get(0); } IsotopeContainer();  IsotopeContainer(IMolecularFormula formula, double intensity);  IsotopeContainer(double mass, double intensity);  IsotopeContainer(IsotopeContainer container); void setFormula(IMolecularFormula formula); void addFormula(IMolecularFormula formula); void setMass(double mass); void setIntensity(double intensity); IMolecularFormula getFormula(); List<IMolecularFormula> getFormulas(); double getMass(); double getIntensity(); @Override Object clone(); @Override String toString();  }
@Test public void testGetFormula() { IsotopeContainer isoC = new IsotopeContainer(); IMolecularFormula formula = builder.newInstance(IMolecularFormula.class); isoC.setFormula(formula); Assert.assertEquals(formula, isoC.getFormula()); }