如何更改Wordpress walker菜单中子菜单锚的输出

如何剥离子菜单中显示的锚点？他们应该只在顶级中包围锚，但不幸的是，它会添加到所有锚中：

<ul class="menu">
    <li>
        <h2><a>First Item</a><h2>
        <ul class="sub-menu">
            <li><h2><a>Sub item</a><h2><li>     //<----- h2 tag, bad. :(
        <ul>
    <li>
</ul>

我正在努力实现：

    <ul class="menu">
    <li>
        <h2><a>First Item</a><h2>
        <ul class="sub-menu">
            <li><a>Sub item</a><li>   //<----- no h2, good. :)
        <ul>
    <li>
</ul>

目前使用这个助行器类：

class Description_Walker extends Walker_Nav_Menu
{
/**
 * Start the element output.
 *
 * @param  string $output Passed by reference. Used to append additional content.
 * @param  object $item   Menu item data object.
 * @param  int $depth     Depth of menu item. May be used for padding.
 * @param  array $args    Additional strings.
 * @return void
 */
function start_el(&$output, $item, $depth, $args)
{
    $classes     = empty ( $item->classes ) ? array () : (array) $item->classes;
    $class_names = join(
        ' '
    ,   apply_filters(
            'nav_menu_css_class'
        ,   array_filter( $classes ), $item
        )
    );
    ! empty ( $class_names )
        and $class_names = ' class="'. esc_attr( $class_names ) . '"';
    $output .= "<li id='menu-item-$item->ID' $class_names>";
    $attributes  = '';
    ! empty( $item->attr_title )
        and $attributes .= ' title="'  . esc_attr( $item->attr_title ) .'"';
    ! empty( $item->target )
        and $attributes .= ' target="' . esc_attr( $item->target     ) .'"';
    ! empty( $item->xfn )
        and $attributes .= ' rel="'    . esc_attr( $item->xfn        ) .'"';
    ! empty( $item->url )
        and $attributes .= ' href="'   . esc_attr( $item->url        ) .'"';
    // insert description for top level elements only
    // you may change this
    $description = ( ! empty ( $item->description ) and 0 == $depth )
        ? '<small class="nav_desc">' . esc_attr( $item->description ) . '</small>' : '';
    $title = apply_filters( 'the_title', $item->title, $item->ID );
    $item_output = $args->before
        . "<h2><a $attributes>"
        . $args->link_before
        . $title
        . '</a></h2>'
        . $args->link_after
        . $description
        . $args->after;
    // Since $output is called by reference we don't need to return anything.
    $output .= apply_filters(
        'walker_nav_menu_start_el'
    ,   $item_output
    ,   $item
    ,   $depth
    ,   $args
    );
}

}