code: public void attempt(Request request) {
      this.attempt(request, new APICallback() {
        @Override
        public void error(Exception ex) {
        }
  
        public void response(Response r) {
        }
      });
    }
docs: Attempt an API call. This method executes the API call asynchronously
  on an internal thread pool. If the call is rate limited, the thread
  will retry up to the maximum configured time.
  @param request the API request.