{
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    {
      "id": "n1",
      "label": "No Link"
    },
    {
      "id": "n2",
      "label": "Link To Java",
      "url": "java/content-extraction"
    },
    {
      "id": "n3",
      "label": "Link to External",
      "url": "http://commonmark.org"
    }
  ],
  "edges": [
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    ["n3", "n2"]
  ]
}