diff --git a/library/Perfdatagraphsprometheus/Client/Prometheus.php b/library/Perfdatagraphsprometheus/Client/Prometheus.php
index 89882cf..a95967c 100644
--- a/library/Perfdatagraphsprometheus/Client/Prometheus.php
+++ b/library/Perfdatagraphsprometheus/Client/Prometheus.php
@@ -23,7 +23,7 @@ class Prometheus
     protected const QUERYRANGE_ENDPOINT = '/api/v1/query_range';
 
     /** @var $this \Icinga\Application\Modules\Module */
-    protected $client = null;
+    protected Client $client;
 
     protected string $URL;
     protected int $maxDataPoints;
diff --git a/library/Perfdatagraphsprometheus/Client/Transformer.php b/library/Perfdatagraphsprometheus/Client/Transformer.php
index 2825fbe..919ab9c 100644
--- a/library/Perfdatagraphsprometheus/Client/Transformer.php
+++ b/library/Perfdatagraphsprometheus/Client/Transformer.php
@@ -22,14 +22,10 @@ class Transformer
      * output format we need.
      *
      * @param GuzzleHttp\Psr7\Response $response the data to transform
-     * @param array $includeMetrics metrics to include in the response
-     * @param array $excludeMetrics metrics to exlude from the response
      * @return PerfdataResponse
      */
-    public static function transform(
-        Response $response,
-        array $excludeMetrics = [],
-    ): PerfdataResponse {
+    public static function transform(Response $response): PerfdataResponse
+    {
         $pfr = new PerfdataResponse();
 
         if (empty($response)) {
@@ -40,7 +36,7 @@ public static function transform(
         $body = json_decode($response->getBody()->getContents(), true);
 
         if ($body['status'] !== 'success') {
-            $perfdataresponse->addError($body['error'] ?? 'unknown error');
+            $pfr->addError($body['error'] ?? 'unknown error');
             return $pfr;
         }