private static void WriteFragmentToConsole(Fragment frag)
{
IChemicalFormula formula = frag as IChemicalFormula;
string f = "";
if (formula != null)
f = formula.ChemicalFormula.ToString();
Console.WriteLine("{0,-4} {1,-20} {2,10:F5} {3,10:F5} {4,-5}", frag, f, frag.MonoisotopicMass, frag.ToMz(1), frag.GetSequence());
}