docs: def change_numbering(self, rename_dict, inplace=False):
          """Return the reindexed version of Cartesian.
  
          Args:
              rename_dict (dict): A dictionary mapping integers on integers.
  
          Returns:
              Cartesian: A renamed copy according to the dictionary passed.
          """
          output = self if inplace else self.copy()
          new_index = [rename_dict.get(key, key) for key in self.index]
          output.index = new_index
          if not inplace:
              return output