Recombine the applied objects like the original.

def _combine(self, applied, shortcut=False):
        """Recombine the applied objects like the original."""
        applied_example, applied = peek_at(applied)
        coord, dim, positions = self._infer_concat_args(applied_example)
        if shortcut:
            combined = self._concat_shortcut(applied, dim, positions)
        else:
            combined = concat(applied, dim)
            combined = _maybe_reorder(combined, dim, positions)

        if isinstance(combined, type(self._obj)):
            # only restore dimension order for arrays
            combined = self._restore_dim_order(combined)
        if coord is not None:
            if shortcut:
                combined._coords[coord.name] = as_variable(coord)
            else:
                combined.coords[coord.name] = coord
        combined = self._maybe_restore_empty_groups(combined)
        combined = self._maybe_unstack(combined)
        return combined