recursive tree data

recursive_tree.json

{
  "value": 1,
  "children": [
    {
      "value": 2,
      "children": [
        {
          "value": 5
        },
        {
          "value": 6,
          "comment": "upper six"
        },
        {
          "value": 7
        }
      ]
    },
    {
      "value": 3,
      "children": [
        {
          "value": 5
        },
        {
          "value": 6,
          "comment": "flat six"
        },
        {
          "value": 7,
          "children": [
            {
              "value": 2
            },
            {
              "value": 6,
              "comment": "down six"
            },
            {
              "value": 4
            }
          ]
        }
      ]
    }
  ]
}