public function set_order_master(\collection $collection, $bool)
    {
        $sql = "UPDATE basusr SET order_master = :master WHERE usr_id = :usr_id AND base_id = :base_id";

        $stmt = $this->app->getApplicationBox()->get_connection()->prepare($sql);
        $stmt->execute([
            ':master'    => $bool ? 1 : 0,
            ':usr_id'    => $this->user->getId(),
            ':base_id'   => $collection->get_base_id()
        ]);
        $stmt->closeCursor();

        return $this;
    }