Recombine the applied objects like the original.

def _combine(self, applied):
        """Recombine the applied objects like the original."""
        applied_example, applied = peek_at(applied)
        coord, dim, positions = self._infer_concat_args(applied_example)
        combined = concat(applied, dim)
        combined = _maybe_reorder(combined, dim, positions)
        if coord is not None:
            combined[coord.name] = coord
        combined = self._maybe_restore_empty_groups(combined)
        combined = self._maybe_unstack(combined)
        return combined