def METHOD_NAME(self, request, queryset):
    if not request.user.has_perm('questionnaires.change_session'):
        messages.add_message(request, messages.ERROR, 'You have no permission to freeze Sessions')
        return
    total_count = queryset.count()
    frozen_pre_count = queryset.filter(frozen=True).count()
    if total_count == frozen_pre_count:
        messages.add_message(request, messages.WARNING, 'All selected Session objects are already frozen')
        return
    queryset.exclude(frozen=True).update(frozen=True)
    frozen_post_count = queryset.filter(frozen=True).count()
    messages.add_message(request, messages.SUCCESS, f'{frozen_post_count-frozen_pre_count} Sessions frozen')