text: 
  class Ion_series(object):
      def __init__(self, mzid_info):
          self.fragtype = mzid_info['name']
          self.charge = mzid_info['charge']
          self.ions_index = mzid_info['index']
          for peak_info in mzid_info['FragmentArray']:
              if peak_info['measure_ref'] == 'm_mz':
                  self.mz_ary = peak_info['values']
              elif peak_info['measure_ref'] == 'm_intensity':
                  self.int_ary = peak_info['values']
              elif peak_info['measure_ref'] == 'm_error':
                  pass
              else:
                  raise ValueError("not known identifier")
  