code: def add_semantic_hub_layout(cx, hub):
      
      graph = cx_to_networkx(cx)
      hub_node = get_node_by_name(graph, hub)
      node_classes = classify_nodes(graph, hub_node)
      layout_aspect = get_layout_aspect(hub_node, node_classes)
      cx['cartesianLayout'] = layout_aspect
docs: Attach a layout aspect to a CX network given a hub node.