<?php
    //creeaza obiectul clasei
    $myMenuWalker = new Custom_Menu_Walker();

    //parcurge meniul cu id-ul 4, pentru a genera itemii
    wp_nav_menu(array('walker'=>$myMenuWalker, 'container'=>null, 'menu_class'=>'topmost_menu', 'menu'=>4, 'echo'=>false));

    if(count($myMenuWalker->ArrayItems)):
    //afiseaza meniul
?>
    <ul class="custom_menu">
        <?php foreach ($myMenuWalker->ArrayItems as $item):?>
        <li><a href="<?=$item['url']?>"><?=$item['title']?></a></li>
        <li>&nbsp;/&nbsp;</li>
        <?php endforeach;?>
        <li><a href="#myCustomId" target="_self">Un link in plus</a></li>
    </ul>
<?php endif;?>