update null serialization

Account/NullGroup.php

@@ -35,4 +35,12 @@ final class NullGroup extends Group
     {
         $this->id = $id;
     }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function jsonSerialize() : mixed
+    {
+        return ['id' => $this->id];
+    }
 }

DataStorage/Cache/Connection/NullCache.php

@@ -157,4 +157,12 @@ final class NullCache extends ConnectionAbstract
     {
         return true;
     }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function jsonSerialize() : mixed
+    {
+        return ['id' => $this->id];
+    }
 }

DataStorage/Database/Connection/NullConnection.php

@@ -30,4 +30,12 @@ final class NullConnection extends ConnectionAbstract
     public function connect(array $dbdata = null) : void
     {
     }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function jsonSerialize() : mixed
+    {
+        return ['id' => $this->id];
+    }
 }

DataStorage/Database/Connection/NullPDO.php

@@ -32,4 +32,12 @@ final class NullPDO extends \PDO
     public function __construct()
     {
     }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function jsonSerialize() : mixed
+    {
+        return ['id' => $this->id];
+    }
 }

Localization/NullLocalization.php

@@ -35,4 +35,12 @@ final class NullLocalization extends Localization
     {
         $this->id = $id;
     }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function jsonSerialize() : mixed
+    {
+        return ['id' => $this->id];
+    }
 }

Module/NullModule.php

@@ -44,4 +44,12 @@ final class NullModule extends ModuleAbstract
                 ]
             );
     }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function jsonSerialize() : mixed
+    {
+        return ['id' => $this->id];
+    }
 }