CodeIgniter custom_result_object类参数

In my model I have:

function select_by_limit($start, $limit) {
    $this->db->from($this->_table.' a');
    $this->db->join('zone b', "a.id_zona = b.id_zona", 'left');
    $this->db->join('tip_proprietate c', "a.id_tip_proprietate = c.id_tip_proprietate");
    $this->db->limit($limit, $start);
    $query = $this->db->get_compiled_select();
    $result = $this->db->query($query);
    return $result->custom_result_object('Proprietati');
}

So I use custom object class Proprietati. But how can I send a parameter so I can get it in constructor?

public function __construct($resolution = 270){
    $this->_resolution = $resolution;
}

Controller

class foo extends CI_Controller {
    protected $_resolution;

    public function __construct($resolution = 270){
        $this->_resolution = $resolution;
    }

To pass $resolution to the model function

public function using_model($start, $limit, $this->resolution);

In the model

function select_by_limit($start, $limit, $resolution) {
    //whatever happens here....