json_schema: {
      "optional": true,
      "properties": {
          "comment": {
              "type": "string"
          },
          "eTag": {
              "type": "string"
          },
          "expires": {
              "pattern": "^(\\d{4})(-)?(\\d\\d)(-)?(\\d\\d)(T)?(\\d\\d)(:)?(\\d\\d)(:)?(\\d\\d)(\\.\\d+)?(Z|([+-])(\\d\\d)(:)?(\\d\\d))?",
              "type": "string"
          },
          "hitCount": {
              "type": "integer"
          },
          "lastAccess": {
              "pattern": "^(\\d{4})(-)?(\\d\\d)(-)?(\\d\\d)(T)?(\\d\\d)(:)?(\\d\\d)(:)?(\\d\\d)(\\.\\d+)?(Z|([+-])(\\d\\d)(:)?(\\d\\d))?",
              "type": "string"
          }
      },
      "required": [
          "lastAccess",
          "eTag",
          "hitCount"
      ],
      "type": "object"
  }