Chamando método CodeIgniter

<?php
    class some_model extends CI_Model{
        public some_method(){
            // Do something
        }
    }
?>
<?php
    class somectrl extends CI_Controller{

        public __construct(){
            parent::__construct();
            $this->load->model("some_model"); // carregamento do model
        }
        public some_method(){
            $this->some_model->some_method(); // método do model
        }
    }
?>