json_schema: {
      "$schema": "http://json-schema.org/draft-04/schema#",
      "type": "object",
      "properties": {
          "tags": {
              "type": "array",
              "minItems": 2,
              "maxItems": 4,
              "items": {
                  "type": "string"
              },
              "additionalItems": false
          }
      },
      "additionalProperties": false,
      "required": [
          "tags"
      ]
  }