From f34679b5ba849e940a097cc01ddf90f1a2bc1b24 Mon Sep 17 00:00:00 2001
From: Rich Lott / Artful Robot <forums@artfulrobot.uk>
Date: Thu, 28 Oct 2021 07:26:41 +0100
Subject: [PATCH] Allow NULL as valid parameter for isRetryableServerError

---
 lib/RetryMiddlewareFactory.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/RetryMiddlewareFactory.php b/lib/RetryMiddlewareFactory.php
index 3ed339b8..b313eb99 100644
--- a/lib/RetryMiddlewareFactory.php
+++ b/lib/RetryMiddlewareFactory.php
@@ -90,7 +90,7 @@ private static function isConnectionError(\GuzzleHttp\Exception\TransferExceptio
      *
      * @return boolean
      */
-    private static function isRetryableServerError(\GuzzleHttp\Psr7\Response $response = null)
+    private static function isRetryableServerError(?\GuzzleHttp\Psr7\Response $response = null)
     {
         if ($response) {
             $statusCode = $response->getStatusCode();