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  <div class="widget widget-sales-top">
    <h6>Топ-продаж</h6>
    <?
      // Get the nav menu based on $menu_name (same as 'theme_location' or 'menu' arg to wp_nav_menu)
      // This code based on wp_nav_menu's code to get Menu ID from menu slug
      $menu_name = 'sidebar-menu'; // change this if necessary

      if ( ( $locations = get_nav_menu_locations() ) && isset( $locations[ $menu_name ] ) ) {
          $menu = wp_get_nav_menu_object( $locations[ $menu_name ] );
          $menu_items = wp_get_nav_menu_items($menu->term_id);
          $menu_list = '<ul id="' . $menu_name . '">';
          foreach ( (array) $menu_items as $key => $menu_item ) {
              $title = $menu_item->title;
              $url = $menu_item->url;
              $mid = $menu_item->object_id;
              if(has_post_thumbnail($mid)) {
                  $thumbnail = get_the_post_thumbnail( $mid, 'thumb' );
              }
              $menu_list .= '<li><a href="' . $url . '"><span class="thumb">' .$thumbnail. '</span>' . $title . '</a></li>';
          }
          $menu_list .= '</ul>';
       } else {
          $menu_list = '<ul><li>Menu "' . $menu_name . '" not defined.</li></ul>';
       }
      // $menu_list now ready to output
       echo $menu_list;
    ?>
  </div><!-- widget widget-sales-top -->