Allowing WalmartProductResultContentSpecification to contain nulls

Author: qschmick

src/DTOs/Walmart/WalmartProductResultContentSpecification.php

@@ -7,7 +7,7 @@
 class WalmartProductResultContentSpecification extends Data
 {
     public function __construct(
-        public readonly string $key,
-        public readonly string $value,
+        public readonly ?string $key = null,
+        public readonly ?string $value = null,
     ) {}
 }