[gnome-music/wip/mschraal/type-checking: 1/2] grltrackerwrapper: Cleanup list comprehension

[Marinus Schraal <mschraal src gnome org>]

commit 80e2f7f7f287ea3fde1fbeda9dfb623fe902f586
Author: Marinus Schraal <mschraal gnome org>
Date:   Mon Oct 19 15:59:34 2020 +0200

    grltrackerwrapper: Cleanup list comprehension
    
    The old method returned an empty list, which trips up the type
    checker.

 gnomemusic/grilowrappers/grltrackerwrapper.py | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)
---
diff --git a/gnomemusic/grilowrappers/grltrackerwrapper.py b/gnomemusic/grilowrappers/grltrackerwrapper.py
index 4d30a522..cc4338f0 100644
--- a/gnomemusic/grilowrappers/grltrackerwrapper.py
+++ b/gnomemusic/grilowrappers/grltrackerwrapper.py
@@ -159,8 +159,10 @@ class GrlTrackerWrapper(GObject.GObject):
         if change_type not in self._batch_changed_media_ids.keys():
             self._batch_changed_media_ids[change_type] = []
 
-        [self._batch_changed_media_ids[change_type].append(media.get_id())
-         for media in medias if media.is_audio() or media.is_container()]
+        changed_medias = [
+            media.get_id() for media in medias
+            if media.is_audio() or media.is_container()]
+        self._batch_changed_media_ids[change_type].extend(changed_medias)
 
         if self._content_changed_timeout == 0:
             self._content_changed_timeout = GLib.timeout_add(