Merge pull request #983 from ongr-io/7.0

fixed normalization of null embedded objects

Author: einorler

Mapping/Converter.php

@@ -47,6 +47,10 @@ public function convertDocumentToArray($document): array
 
     protected function normalize($document, $metadata = null)
     {
+        if ($document === null) {
+            return null;
+        }
+
         $metadata = $metadata ?? $this->propertyMetadata[get_class($document)];
         $result = [];