title: wp_nav_menu_items not working for child theme
body: <p>I am developing the plugin in wordpress to add menu item using </p>
  
  <pre><code>add_filter('wp_nav_menu_items', 'your_custom_menu_item',10,2);
  function your_custom_menu_item ( $items, $args ) {
          $items.="&lt;li&gt;Testing Menu&lt;/li&gt;";
          return $items;
  }
  </code></pre>
  
  <p>In parent theme it appends new menu item to current menu, the problem is its not working with child theme.
  anyone can help me please?</p>