/**
    * @param int advisors id
    * @return array
    * @final
    */
    final public function getClients($advisors = null) {
        $fluent = $this->db->select("id, CONCAT_WS(' ', id, titul, prijmeni, jmeno) AS klient")->from(self::clientsTable);
        if($advisors != null)
            $fluent->where('poradce = %i', $advisors);
        return $fluent->OrderBy('zalozen DESC')->fetchPairs('id', 'klient');
    }