code: public void initialize(AbstractGoogleClientRequest<?> request) throws IOException {
      if (key != null) {
        request.put("key", key);
      }
      if (userIp != null) {
        request.put("userIp", userIp);
      }
    }
docs: Subclasses should call super implementation in order to set the key and userIp.
  
  @throws IOException I/O exception