output.json

{
  "entities": {
    "users": {
      "123": {
        "id": "123",
        "name": "Paul",
        "posts": [
          "1",
          "2"
        ],
        "comments": [
          "250"
        ]
      },
      "245": {
        "id": "245",
        "name": "Jane",
        "comments": [
          "249",
          "251"
        ],
        "posts": []
      },
      "246": {
        "id": "246",
        "name": "Spambot5000",
        "comments": [
          "252"
        ]
      }
    },
    "comments": {
      "249": {
        "id": "249",
        "content": "Nice post!",
        "commenter": "245",
        "post": "1"
      },
      "250": {
        "id": "250",
        "content": "Thanks!",
        "commenter": "123",
        "post": "1"
      },
      "251": {
        "id": "251",
        "content": "Your other post was nicer",
        "commenter": "245",
        "post": "2"
      },
      "252": {
        "id": "252",
        "content": "I am a spammer!",
        "commenter": "246",
        "post": "2"
      }
    },
    "posts": {
      "1": {
        "id": "1",
        "title": "My first post!",
        "author": "123",
        "comments": [
          "249",
          "250"
        ]
      },
      "2": {
        "id": "2",
        "title": "This other post",
        "author": "123",
        "comments": [
          "251",
          "252"
        ]
      }
    }
  },
  "result": [
    "1",
    "2"
  ]
}