Notifications accept.

src/snek/service/notification.py

@@ -6,9 +6,12 @@ class NotificationService(BaseService):
 
     async def mark_as_read(self, user_uid, channel_message_uid):
         model = await self.get(user_uid, object_uid=channel_message_uid)
+        if not model:
+            return False 
         model['read_at'] = now()
         await self.save(model)
-
+        return True 
+    
     async def get_unread_stats(self,user_uid):
         records = await self.query("SELECT object_type, COUNT(*) as count FROM notification WHERE user_uid=:user_uid AND read_at IS NULL GROUP BY object_type",dict(user_uid=user_uid))