### Question:
IsotopeContainer { public void setMass(double mass) { masOs = mass; } 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();  }### Answer:
@Test public void testSetMass_double() { IsotopeContainer isoC = new IsotopeContainer(); isoC.setMass(130.00); Assert.assertNotNull(isoC); }