json_schema: {
      "$schema": "http://json-schema.org/draft-04/schema#",
      "definitions": {
          "ThingWithCodes": {
              "type": "object",
              "additionalProperties": true,
              "title": "Thing with Codes schema.",
              "description": "An explanation about the purpose of this instance described by this schema.",
              "properties": {
                  "codes": {
                      "type": "object",
                      "minItems": 0,
                      "additionalProperties": true,
                      "title": "codes schema.",
                      "description": "An explanation about the purpose of this instance described by this schema.",
                      "items": {}
                  }
              }
          }
      },
      "properties": {
          "ThingWithCodes": {
              "$ref": "#/definitions/ThingWithCodes"
          }
      },
      "required": [
          "ThingWithCodes"
      ]
  }