如何在Django的管理日志中添加可排序列

class MyModel(models.Model):
    ...

    @property
    def admin_last_modified(self):
        from django.contrib.admin.models import LogEntry
        from django.contrib.contenttypes.models import ContentType
        try:
            logentry = LogEntry.objects.filter(
                object_id=self.pk,
                content_type_id=ContentType.objects.get_for_model(self.__class__)
            ).order_by('action_time')[0]
        except:
            return ''
        return '{} by {}'.format(logentry.action_time, logentry.user)

管理类:

@admin.register(MyModel)
class MyAdmin(admin.ModelAdmin):
    list_display = ( ..., 'admin_last_modified' )

为此,根据我收集到的信息,我需要将这个属性重新表述为某种注释。但我试过却没有想出一个办法:

class MyAdmin(admin.ModelAdmin):

   def get_queryset(self):
       queryset = super().get_queryset(request)
       queryset = queryset.annotate(
           admin_last_modified=# ???
       )
       return queryset

我现在在找什么来代替问号。