return null explicitly

Author: dbu

Diff for: src/PHPCR/Shell/Serializer/NodeNormalizer.php

@@ -154,7 +154,7 @@ public function denormalize($data, $class, $format = null, array $context = []):
         // Add new properties
         foreach ($data as $pName => $datum) {
             $datum = $this->normalizeDatum($datum);
-            $pValue = isset($datum['value']) ? $datum['value'] : null;
+            $pValue = $datum['value'] ?? null;
             $pType = isset($datum['type']) ? PropertyType::valueFromName($datum['type']) : null;
 
             if ($pValue !== null) {
@@ -168,6 +168,8 @@ public function denormalize($data, $class, $format = null, array $context = []):
                 implode("\n", $errors)
             ));
         }
+
+        return null;
     }
 
     /**