code: public void log(Throwable error, Map<String, Object> custom, String description) {
      log(error, custom, description, null);
    }
docs: Record an error with custom parameters and human readable description at the default level
  returned by {@link com.rollbar.notifier.Rollbar#level}.
  
  @param error       the error.
  @param custom      the custom data.
  @param description the human readable description of error.