related_book_tags = models.Tag.objects.usage_for_queryset(
objects, counts=True).exclude(
category='set').exclude(pk__in=tags_pks)
else:
if tags:
related_book_tags = models.Tag.objects.usage_for_queryset(
objects, counts=True).exclude(
category='set').exclude(pk__in=tags_pks)
else:
if tags: