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.

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