code: private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
          GetField fields = in.readFields();
          principal = (String) fields.get(PRINCIPAL, null);
          jwt = (String) fields.get(JWT, null);
          type = (String) fields.get(TYPE, null);
          handleClaims(jwt);
      }
docs: Deserialize json web token.
  
  @param in
  The stream from which this object is read.
  
  @throws IOException
  @throws ClassNotFoundException