public function getTarget($nb_site_target)
    {
        $nb_site_target_id = nb_getMixedValue($nb_site_target, 'nb_site_target_id');

        return (is_numeric($nb_site_target_id) || nb_isValidGUID($nb_site_target_id))
               ? $this->nb_site_target_list->getItem($nb_site_target_id)->setSite($this)
               : null
        ;
    }