Unable to Change "Pages:" Before WP_LINK_PAGES

Question

Below is a functions.php code for wp_link_pages which allows pagination and previous/next links to be displayed. It also wraps each pagination link in a span class called "classlinks".

I need to change the default "Pages:" before the pagination while maintaining the rest of the code. My attempts removed the ability to show both next/previous links and pagination. Any help?

// WP_LINK_PAGES: Add prev and next links to a numbered link list
add_filter('wp_link_pages_args', 'wp_link_pages_args_prevnext_add');

    function wp_link_pages_args_prevnext_add($args)
{
    global $page, $numpages, $more, $pagenow;

    if($page-1) # there is a previous page
        $args['before'] .= ' '. _wp_link_page($page-1) 
            . $args['link_before'] . $args['previouspagelink']  . '</a>' . ' '
        ;

    if ($page<$numpages) # there is a next page
        $args['after'] = ' '. _wp_link_page($page+1)
           . $args['link_before'] . $args['nextpagelink']  . '</a>'
        ;

    $args['link_before'] = '<span class="classlinks">';
    $args['link_after'] = '</span>';

    return $args;
}

Answer 1

Add, right after the declaration of the global vars, e.g.: $args['before'] = '<p>Hello world: ';