public void ChemicalForulaIsNotSubSet()
        {
            ChemicalFormula formulaA = new ChemicalFormula("C2H3NO");
            ChemicalFormula formulaB = new ChemicalFormula("C3H2NO");

            Assert.IsFalse(formulaA.IsSubSetOf(formulaB));
        }
        public void ChemicalForulaIsSubSet()
        {
            ChemicalFormula formulaA = new ChemicalFormula("C2H3NO");
            ChemicalFormula formulaB = new ChemicalFormula("C3H3NO");

            Assert.IsTrue(formulaA.IsSubSetOf(formulaB));
        }