Cast Guzzle Response Body as String so that GuzzleHttp\json_decode() will accept it.

Author: jbeales

src/Metric/v1/Gnocchi/Models/Resource.php

@@ -131,8 +131,7 @@ public function getMetricMeasures(array $options = []): array
         );
 
         $response = $this->execute($this->api->getResourceMetricMeasures(), $options);
-
-        return \GuzzleHttp\json_decode($response->getBody());
+        return \GuzzleHttp\json_decode((string) $response->getBody());
     }
 
     /**