JGraphT:如何使用JSONImporter导入带有标记边的DirectedMultigraph

DirectedMultigraph<String, DefaultEdge> graph = new DirectedMultigraph<>(DefaultEdge.class);

{
  "vertices": ["A", "B", "C"],
  "edges": [
    {"source": "A", "target": "B", "label": "Edge 1"},
    {"source": "B", "target": "C", "label": "Edge 2"},
    {"source": "C", "target": "A", "label": "Edge 3"}
  ]
}

JSONImporter<String, DefaultEdge> importer = new JSONImporter<>();
importer.importGraph(graph, new StringReader(jsonString));

Set<String> vertices = graph.vertexSet();
Set<DefaultEdge> edges = graph.edgeSet();

for (DefaultEdge edge : edges) {
    String label = graph.getEdge(edge);
    System.out.println("Edge label: " + label);
}