refacto: remove useless function toReadableHeaderValue

src/Http/TracedResponse.php

@@ -51,29 +51,6 @@ public function getHeaders(bool $throw = true): array
         return $this->response->getHeaders($throw);
     }
 
-    private function toReadableHeaderValue(mixed $value): string
-    {
-        if (null === $value) {
-            return 'null';
-        } elseif (\is_array($value)) {
-            return implode(', ', array_map([$this, __FUNCTION__], $value));
-        } elseif (\is_scalar($value)) {
-            if (\is_bool($value)) {
-                return true === $value ? 'true' : 'false';
-            }
-
-            return (string) $value;
-        } elseif (\is_object($value)) {
-            if (method_exists($value, '__toString')) {
-                return (string) $value;
-            }
-
-            return '(object)#'.$value::class;
-        }
-
-        return \gettype($value);
-    }
-
     public function getContent(bool $throw = true): string
     {
         try {