[
  {
    "id" : 0,
    "child_ids" : [
      1,
      2
    ],
    "attributes": {
      "label" : "Node-0"
    }
 }
 {
    "id" : 1,
    "child_ids" : [
      3,
      4
    ],
    "attributes": {
      "label" : "Node-1"
    }
 }
]