public void ClearCTerminusMod()
{
ChemicalFormula formula = new ChemicalFormula("Fe");
_mockPeptideEveryAminoAcid.SetModification(formula, Terminus.C);
_mockPeptideEveryAminoAcid.ClearModifications(Terminus.C);
Assert.IsNull(_mockPeptideEveryAminoAcid.CTerminusModification);
}