Merge pull request #495 from okaufmann/implicit-nullables

Fix Remaining Nullable Parameter Definitions

Author: freekmurze

docs/advanced-usage/using-your-own-event-serializer.md

@@ -34,7 +34,7 @@ the currency.
 ```
 class UpgradeSerializer extends JsonEventSerializer
 {
-    public function deserialize(string $eventClass, string $json, string $metadata = null): ShouldBeStored
+    public function deserialize(string $eventClass, string $json, ?string $metadata = null): ShouldBeStored
     {
         $event = parent::deserialize($eventClass, $json, $metadata);
 

src/EventSerializers/EventSerializer.php

@@ -12,6 +12,6 @@ public function deserialize(
         string $eventClass,
         string $json,
         int $version,
-        string $metadata = null
+        ?string $metadata = null
     ): ShouldBeStored;
 }

src/EventSerializers/JsonEventSerializer.php

@@ -37,7 +37,7 @@ public function deserialize(
         string $eventClass,
         string $json,
         int $version,
-        string $metadata = null
+        ?string $metadata = null
     ): ShouldBeStored {
         return $this->serializer->deserialize($json, $eventClass, 'json');
     }