redef fun visit_all(v: Visitor) do end
redef fun visit_all_reverse(v: Visitor) do end
redef fun replace_child(old_child: PNode, new_child: nullable PNode) do end
redef fun visit_all(v: Visitor) do end
redef fun visit_all_reverse(v: Visitor) do end
redef fun replace_child(old_child: PNode, new_child: nullable PNode) do end