new: [UUID] behaviour added

- auto set UUIDs on objects

app/src/Model/Behavior/UUIDBehavior.php

@@ -0,0 +1,18 @@
+<?php
+namespace App\Model\Behavior;
+
+use Cake\ORM\Behavior;
+use Cake\Event\EventInterface;
+use Cake\Datasource\EntityInterface;
+use ArrayObject;
+use Cake\Utility\Text;
+
+class UUIDBehavior extends Behavior
+{
+    public function beforeSave(EventInterface $event, EntityInterface $entity, ArrayObject $options)
+    {
+        if ($entity->isNew() && empty($entity['uuid'])) {
+            $entity['uuid'] = Text::uuid();
+        }
+    }
+}