def _add_tile(self, new_tile, ijk):
        """Add a tile with a label indicating its tiling position. """
        tile_label = "{0}_{1}".format(self.name, '-'.join(str(d) for d in ijk))
        self.add(new_tile, label=tile_label, inherit_periodicity=False)
Add a tile with a label indicating its tiling position.