Fix get_objects to accept start_qs and additional_filter

aleksis/apps/chronos/models.py

@@ -518,10 +518,18 @@ class LessonEvent(CalendarEvent):
         if prefetch_absences:
             prefetch_fields.append("teachers__kolego_absences")
 
+        if "start_qs" in kwargs:
+            start_qs = kwargs.pop("start_qs")
+        else:
+            start_qs = cls.objects.not_instance_of(SupervisionEvent)
+
+        if "additional_filter" in kwargs:
+            q = q & kwargs.pop("additional_filter")
+
         objs = super().get_objects(
             request,
             params,
-            start_qs=cls.objects.not_instance_of(SupervisionEvent),
+            start_qs=start_qs,
             additional_filter=q,
             select_related=["subject", "course"],
             prefetch_related=prefetch_fields,