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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def add_semantic_hub_layout(cx, hub):
 """Attach a layout aspect to a CX network given a hub node."""

    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