docs: def get_indexer_nd(index, labels, method=None, tolerance=None):
      """ Call pd.Index.get_indexer(labels). """
      kwargs = _index_method_kwargs(method, tolerance)
  
      flat_labels = np.ravel(labels)
      flat_indexer = index.get_indexer(flat_labels, **kwargs)
      indexer = flat_indexer.reshape(labels.shape)
      return indexer