docs: def match_best_pdb_chains(pdb1, pdb1_name, pdb2, pdb2_name, cut_off = 60.0, use_seqres_sequences_if_possible = True):
      '''A wrapper function for match_pdb_chains. This function only takes the best match. The return
          value is a dict mapping
              chain_id_in_pdb1 -> None or a tuple (chain_id_in_pdb_2, percentage_identity_score)
         where percentage_identity_score is a float. e.g. 'A' -> ('B', 100).'''
      d = match_pdb_chains(pdb1, pdb1_name, pdb2, pdb2_name, cut_off = cut_off, allow_multiple_matches = False, use_seqres_sequences_if_possible = use_seqres_sequences_if_possible)
      for k, v in d.iteritems():
          if v:
              d[k] = v[0]
      return d