public function setDraftVersionFilter($enabled = true)
    {
        if ($this->em->getFilters()->isEnabled('draft') && ! $enabled) {
            $this->em->getFilters()->disable('draft');
        } else if (! $this->em->getFilters()->isEnabled('draft') && $enabled) {
            $this->em->getFilters()->enable('draft');
        }
    }