Removed non-universal getData call in ResponseResolver's getResponseContent function. It is not required.

src/Tools/ResponseResolver.php

@@ -75,6 +75,6 @@ class ResponseResolver
      */
     private function getResponseContent($response)
     {
-        return $response ? $response->getData() : '';
+        return $response ? $response->getContent() : '';
     }
 }