Extending CI_Exceptions

Hello,
I'm trying to extend CI_Exceptions but I can't access the load method in my sub class.
I tried :

PHP Code:

class MY_Exceptions extends CI_Exceptions {

    protected $CI;

    public function __construct()
    {
        parent::__construct();
        $this->CI =& get_instance();
        $this->CI->load->library('SOMELIBRARY');
    } 


Thanks in advance,