public ISpectrum GetSpectrum(int scanNum)
        {
            try
            {
                if (reader.GetMSnOrder(scanNum) == 1)
                {
                    GeneralSpectrum spectrum = new GeneralSpectrum(1, scanNum);
                    List <IPeak>    peaks    = reader.Read(scanNum);
                    spectrum.SetPeaks(peaks);
                    return(spectrum);
                }
                else
                {
                    int msOrder                 = reader.GetMSnOrder(scanNum);
                    TypeOfMSActivation type     = reader.GetActivation(scanNum);
                    double[]           mzCharge = reader.GetParentMZCharge(scanNum);
                    ISpectrum          spectrum = new GeneralSpectrumMSn(msOrder, scanNum, type, mzCharge[0], (int)mzCharge[1]);

                    List <IPeak> peaks = reader.Read(scanNum);
                    spectrum.SetPeaks(peaks);
                    return(spectrum);
                }
            }
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
                return(null);
            }
        }