Create custom Wordpress Walker class

I have a custom walker class that is currently generating a list of links. I need additional features added. Here it is: //[login to view URL] wp_nav_menu(array ( 'theme_location' => 'main_nav', 'container' => '', 'items_wrap' => '<ul class="head-nav">%3$s</ul>', 'walker' => new WPSE_78121_Sublevel_Walker ) ); //[login to view URL] class WPSE_78121_Sublevel_Walker extends Walker_Nav_Menu { function start_lvl( &$output, $depth = 0, $args = array() ) { $indent = str_repeat("\t", $depth); $output .= "\n$indent<div class='sub-menu-wrap sub-level-". $depth ."'><ul class='sub-menu'>\n"; } function end_lvl( &$output, $depth = 0, $args = array() ) { $indent = str_repeat("\t", $depth); $output .= "$indent</ul></div>\n"; } } The output from the walker class needs to do two things: 1. If child links have more than 10 items, split the UL into another UL 2. Generate different markup depending on the 'depth' of child links Please contact me for specific directions Thanks