code: function isSerializable(target, property) {
      // get the class constructor
      const constr = target.constructor;
      // retrieve the current metadata
      const metadata = Reflect.getMetadata(METADATA_doNotSerialize, constr) || {};
      // if doNotSerialize is defined, don't serialize!
      return !metadata.hasOwnProperty(property);
  }
docs: Checks if a given property will be serialized or not