json_schema: {
      "properties": {
          "objectIdFieldName": {
              "title": "field with object identifier ",
              "type": "string"
          },
          "objectIds": {
              "items": {
                  "title": "object identifier",
                  "type": "integer"
              },
              "title": "list of object identifiers",
              "type": "array"
          }
      },
      "title": "set of feature identifiers",
      "type": "object"
  }