[
  {
    "bases": [
      "RepeatedChild"
    ],
    "fields": [
      "value",
      "extra"
    ]
  },
  {
    "payload": {
      "value": [
        1,
        1
      ]
    },
    "source": {
      "value": [
        1,
        1
      ],
      "extra": 1
    },
    "generated": {
      "value": [
        1,
        1
      ],
      "extra": 1
    }
  }
]