{
  "type": "object",
  "additionalProperties": false,
  "required": [
    "parent"
  ],
  "properties": {
    "parent": {
      "type": "object",
      "additionalProperties": false,
      "properties": {
        "child": {
          "type": "string",
          "default": "<placeholder>"
        }
      }
    }
  }
}