title: wordpress wp_nav_menu add span at the end of ul
body: <p>I am using wordpress and wp_nav_menu function to get navigation, and I want to add a span inside ul like this:</p>
  
  <pre><code>&lt;ul&gt;
    &lt;li&gt;&lt;a href=""&gt;url1&lt;/a&gt;&lt;/li&gt;
    &lt;li&gt;&lt;a href=""&gt;url2&lt;/a&gt;&lt;/li&gt;
    &lt;li&gt;&lt;a href=""&gt;url3&lt;/a&gt;&lt;/li&gt;
    &lt;span&gt;&lt;/span&gt; &lt;-- I want to add this
  &lt;/ul&gt;
  </code></pre>
  
  <p>I googled a few times but can't find out what options I have to change in wp_nav_menu</p>
  
  <pre><code>&lt;?php wp_nav_menu( array( 
      'theme_location'  =&gt; 'primary',
      'menu'            =&gt; '',
      'container'       =&gt; 'div',
      'container_class' =&gt; '',
      'container_id'    =&gt; '',
      'menu_class'      =&gt; 'menu',
      'menu_id'         =&gt; '',
      'echo'            =&gt; true,
      'fallback_cb'     =&gt; 'wp_page_menu',
      'before'          =&gt; '',
      'after'           =&gt; '',
      'link_before'     =&gt; '',
      'link_after'      =&gt; '',
      'items_wrap'      =&gt; '&lt;ul id="%1$s" class="%2$s"&gt;%3$s&lt;/ul&gt;',
      'depth'           =&gt; 0,
      'walker'          =&gt; ''
      ) ); ?&gt;
  </code></pre>