CakePHP override Helper function

<?php
// app/View/Helper/CustomMenusHelper.php

App::uses('MenusHelper', 'Menus.View/Helper'); // Croogo's Menu helper

class CustomMenusHelper extends MenusHelper {

    public function __construct(View $view, $settings = array()) {
        parent::__construct($view);
        $this->_setupEvents();
    }
    public function nestedLinks($links, $options = array(), $depth = 1) {
        return 'TEST'; //$output;
    }

}