code: def mzmlfn_kronikfeature_generator(mzmlfns, kronikfns):
      
      for mzmlfn, kronikfn in zip(mzmlfns, kronikfns):
          for quant_el in generate_kronik_feats(kronikfn):
              yield os.path.basename(mzmlfn), quant_el
docs: Generates tuples of spectra filename and corresponding output
      features from kronik