pdf mpdf

<?php if (!defined('BASEPATH')) exit('No direct script access allowed');

class pdf {

    function pdf()
    {
        $CI = & get_instance();
        log_message('Debug', 'mPDF class is loaded.');
    }

    function load($params=NULL)
    {
        include_once APPPATH.'/third_party/mpdf/mpdf.php';

        if ($params == NULL)
        {
    //my question is here, after check link bellow here where is parameter size paper i goes to link but doesn't make me clear ?
    //did this number 10, 10, 10, 10, 6, 3 setting  ?
    //margin_left 15, margin_right 15, margin_top 16, margin_bottom 16, margin_header 9, margin_footer 9 ?


          // check the number of parameters here: http://mpdf1.com/manual/index.php?tid=184
          $params = array("en-GB-x", "A4", "", "", 10, 10, 10, 10, 6, 3, NULL);
        }

//what this param, or this define array above ?
        return new mPDF(
          $param[0],
          $param[1],
          $param[2],
          $param[3],
          $param[4],
          $param[5],
          $param[6],
          $param[7],
          $param[8],
          $param[9],
          $param[10]
        );
    }
}











//controller

// check the number of parameters here: http://mpdf1.com/manual/index.php?tid=184
$overrideParams = array("en-GB-x", "A4", "", "", 10, 10, 10, 10, 6, 3);

//my question is that to overide paper right, we already setting this in library why we should write it again ?

//any way thanks for respond ?