TODO Graph object spanning all entities

{
  "type": "object",
  "properties": {
    "background": {
      "type": "array",
      "items": {
        "type": "string"
      }
    },
    "object_category": {
      "type": "string"
    },
    "object_slim": {
      "type": "string"
    },
    "subject": {
      "type": "array",
      "items": {
        "type": "string"
      }
    }
  },
  "additionalProperties": false
}