docs: def create_spectra_lookup(lookup, fn_spectra):
      """Stores all spectra rt, injection time, and scan nr in db"""
      to_store = []
      mzmlmap = lookup.get_mzmlfile_map()
      for fn, spectrum in fn_spectra:
          spec_id = '{}_{}'.format(mzmlmap[fn], spectrum['scan'])
          mzml_rt = round(float(spectrum['rt']), 12)
          mzml_iit = round(float(spectrum['iit']), 12)
          mz = float(spectrum['mz'])
          to_store.append((spec_id, mzmlmap[fn], spectrum['scan'],
                           spectrum['charge'], mz, mzml_rt, mzml_iit))
          if len(to_store) == DB_STORE_CHUNK:
              lookup.store_mzmls(to_store)
              to_store = []
      lookup.store_mzmls(to_store)
      lookup.index_mzml()