code: def _convert_listlike_indexer(self, keyarr, kind=None):
          
          indexer, keyarr = super()._convert_listlike_indexer(keyarr, kind=kind)
  
          # are we indexing a specific level
          if indexer is None and len(keyarr) and not isinstance(keyarr[0],
                                                                tuple):
              level = 0
              _, indexer = self.reindex(keyarr, level=level)
  
              # take all
              if indexer is None:
                  indexer = np.arange(len(self))
  
              check = self.levels[0].get_indexer(keyarr)
              mask = check == -1
              if mask.any():
                  raise KeyError('%s not in index' % keyarr[mask])
  
          return indexer, keyarr
docs: Parameters
          ----------
          keyarr : list-like
              Indexer to convert.
  
          Returns
          -------
          tuple (indexer, keyarr)
              indexer is an ndarray or None if cannot convert
              keyarr are tuple-safe keys