From 3e60e536f5103e958c8cc6a04d29e4abeb89bc24 Mon Sep 17 00:00:00 2001
From: relikd <info@relikd.de>
Date: Tue, 25 Oct 2022 01:20:48 +0200
Subject: [PATCH] fix: use typing hint for GroupBySource.slug

---
 lektor_groupby/vobj.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/lektor_groupby/vobj.py b/lektor_groupby/vobj.py
index a3c9db5..51019d9 100644
--- a/lektor_groupby/vobj.py
+++ b/lektor_groupby/vobj.py
@@ -55,6 +55,7 @@ class GroupBySource(VirtualSourceObject):
         del self.__children
         del self.__group_map
         # evaluate slug Expression
+        self.slug = None  # type: Optional[str]
         if config.slug and '{key}' in config.slug:
             self.slug = config.slug.replace('{key}', self.key)
         else: