digraph G {
  module [shape=record, label="module\n(e.g., bit-cell array)"];
  design [shape=record, label="design\nDRC_LVS()"];
  hierarchy_layout [shape=record, label="layout\n"];
  hierarchy_spice [shape=record, label="spice\n"];

  module -> design
  design -> hierarchy_layout;
  design -> hierarchy_spice;
}
