public void PeptideCountElements()
{
Peptide pep = new Peptide("G");
pep.AddModification(new OldSchoolModification(1));
Assert.AreEqual(5, pep.ElementCountWithIsotopes("H"));
pep.AddModification(new OldSchoolChemicalFormulaModification(ChemicalFormula.ParseFormula("H{1}")));
Assert.AreEqual(5, pep.ElementCountWithIsotopes("H")); // NOTHING HAS BEEN ADDED!
pep.AddModification(new OldSchoolChemicalFormulaModification(ChemicalFormula.ParseFormula("H{1}"), ModificationSites.G));
Assert.AreEqual(6, pep.ElementCountWithIsotopes("H"));
Isotope isotope = PeriodicTable.GetElement("H").PrincipalIsotope;
Assert.AreEqual(1, pep.SpecificIsotopeCount(isotope));
}