code: private static void fireRetryingEvent(OperationContext opContext, HttpURLConnection request, RequestResult result,
              RetryContext retryContext) {
          if (opContext.getRetryingEventHandler().hasListeners()
                  || OperationContext.getGlobalRetryingEventHandler().hasListeners()) {
              RetryingEvent event = new RetryingEvent(opContext, request, result, retryContext);
              opContext.getRetryingEventHandler().fireEvent(event);
              OperationContext.getGlobalRetryingEventHandler().fireEvent(event);
          }
      }
docs: Fires events representing that a request will be retried.