tools/json-graph/tree.json

{
  "graph": {
    "version": "1.0",
    "type": "tree",
    "directed": true,
    "root": 0,
    "nodes": [
      { "id": 0, "label": "Top" },
      { "id": 1, "label": "Child1" },
      { "id": 2, "label": "Child2" },
      { "id": 3, "label": "Grandchild" }
    ],
    "edges": [
      { "between": [ 0, 1 ] },
      { "between": [ 0, 2 ] },
      { "between": [ 2, 3 ] }
    ]
  }
}