CodyHouse Wordpress Mega Menu

functions.php

// This is the CodyHouse navigation for the clothing tab, it is overkill for the site.
function html5blank_mega()
{
    wp_nav_menu(
    array(
        'theme_location'  => 'header-nav',
        'menu'            => '',
        'container'       => 'nav',
        'container_class' => 'menu-{menu slug}-container',
        'container_id'    => '',
        'menu_class'      => 'cd-nav',
        'menu_id'         => 'cd-primary-nav',
        'echo'            => true,
        'fallback_cb'     => 'wp_page_menu',
        'before'          => '',
        'after'           => '',
        'link_before'     => '',
        'link_after'      => '',
        'items_wrap'      => '<ul class="cd-primary-nav is-fixed">%3$s</ul>',
        'depth'           => 4,
        'walker'          => new html5blank_walker_nav_menu()
        )
    );
}

class html5blank_walker_nav_menu extends Walker_Nav_Menu {

// add classes to ul sub-menus
function start_lvl( &$output, $depth,$item ) {
    // depth dependent classes
    $indent = ( $depth > 0  ? str_repeat( "\t", $depth ) : '' ); // code indent
    $display_depth = ( $depth + 1); // because it counts the first submenu as 0
    $classes = array(
        'sub-menu is-hidden',
        ( $display_depth % 2  ? 'menu-odd' : 'menu-even' ),
        ( $display_depth >=2 ? 'sub-sub-menu is-hidden' : '' ),
        ( $display_depth <2 ? 'cd-secondary-nav' : '' ),
        'menu-depth-' . $display_depth
        );
    $class_names = implode( ' ', $classes );
    $output .= "\n" . $indent . '<ul class="' . $class_names . '"><li class="go-back"><a href="#0">Back</a>'. "\n";

}

// add main/sub classes to li's and links
 function start_el( &$output, $item, $depth, $args ) {
    global $wp_query;
    $indent = ( $depth > 0 ? str_repeat( "\t", $depth ) : '' ); // code indent

    // depth dependent classes
    $depth_classes = array(
        ( $depth == 0 ? '' : 'sub-menu-item' ),
        ( $depth >=2 ? 'sub-sub-menu-item' : '' ),
        ( $depth % 2 ? 'menu-item-odd' : 'menu-item-even' ),
        'menu-item-depth-' . $depth
    );
    $depth_class_names = esc_attr( implode( ' ', $depth_classes ) );

    // passed classes
    $classes = empty( $item->classes ) ? array() : (array) $item->classes;
    $class_names = esc_attr( implode( ' ', apply_filters( 'nav_menu_css_class', array_filter( $classes ), $item ) ) );

    // build html
    $output .= $indent . '<li id="nav-menu-item-'. $item->ID . '" class="' . $depth_class_names . ' ' . $class_names . '">';

    // link attributes
    $attributes  = ! empty( $item->attr_title ) ? ' title="'  . esc_attr( $item->attr_title ) .'"' : '';
    $attributes .= ! empty( $item->target )     ? ' target="' . esc_attr( $item->target     ) .'"' : '';
    $attributes .= ! empty( $item->xfn )        ? ' rel="'    . esc_attr( $item->xfn        ) .'"' : '';
    $attributes .= ! empty( $item->url )        ? ' href="'   . esc_attr( $item->url        ) .'"' : '';
    $attributes .= ' class="menu-link ' . ( $depth > 0 ? 'sub-menu-link' : 'main-menu-link' ) . '"';

    $item_output = sprintf( '%1$s<a%2$s>%3$s%4$s%5$s</a>%6$s',
        $args->before,
        $attributes,
        $args->link_before,
        apply_filters( 'the_title', $item->title, $item->ID ),
        $args->link_after,
        $args->after
    );

    // build html
    $output .= apply_filters( 'walker_nav_menu_start_el', $item_output, $item, $depth, $args );
  }
}

Hi @jaredpalmer, I couldn't also succeed, I include it in my custom plugin I really don't know what I am missing. If possible could you please give some info about proccess to succeed it to work?