chore: better guzzle docs in ApiException

Co-authored-by: Brent Shaffer <betterbrent@google.com>

Author: bshaffer

BigQuery/tests/Unit/Connection/RestTest.php

@@ -214,9 +214,7 @@ private function getMetadata(Request $request)
         // does not; strip them so the metadata line offset matches on both.
         $lines = array_values(array_filter(
             explode(PHP_EOL, (string) $request->getBody()),
-            function ($line) {
-                return strpos($line, 'Content-Length:') !== 0;
-            }
+            fn ($line) => strpos($line, 'Content-Length:') !== 0
         ));
         return json_decode($lines[4], true);
     }

Gax/src/ApiException.php

@@ -346,6 +346,8 @@ public static function createFromRpcStatus(Status $status)
 
     /**
      * Creates an ApiException from a GuzzleHttp RequestException.
+     * In Guzzle 7, this method expects a RequestException with a response.
+     * In Guzzle 8, this method expects a ResponseException.
      *
      * @param RequestException $ex
      * @param boolean $isStream
@@ -357,7 +359,7 @@ public static function createFromRequestException(RequestException $ex, bool $is
         // Guzzle 7 carries the response on RequestException, Guzzle 8 only on
         // its ResponseException subclass, hence the method_exists() check.
         $res = method_exists($ex, 'getResponse') ? $ex->getResponse() : null;
-        $body = (string) $res->getBody();
+        $body = (string) $res?->getBody();
         $decoded = json_decode($body, true);
 
         // A streaming response body will return one error in an array. Parse