From de61dd5302af882b6812895a6e2e9eda80a9b6a3 Mon Sep 17 00:00:00 2001
From: devin <394694181@qq.com>
Date: Wed, 24 May 2023 13:24:25 +0800
Subject: [PATCH] Convert carrier key to string. (#226)

---
 src/Zipkin/Propagation/Map.php | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/src/Zipkin/Propagation/Map.php b/src/Zipkin/Propagation/Map.php
index 01e9ae84..42db47cb 100644
--- a/src/Zipkin/Propagation/Map.php
+++ b/src/Zipkin/Propagation/Map.php
@@ -34,11 +34,8 @@ public function get($carrier, string $key): ?string
                 return null;
             }
 
-            /**
-             * @var string $k
-             */
             foreach ($carrier as $k => $value) {
-                if (strtolower($k) === $lKey) {
+                if (strtolower((string) $k) === $lKey) {
                     return $value;
                 }
             }