Menus WordPress

Aguem pode me explicar cada array desse para eu implementar meu nenu .

<?php $defaults = array(
    'theme_location'  => ,
    'menu'            => ,
    'container'       => 'div',
    'container_class' => 'menu-{menu slug}-container',
    'container_id'    => ,
    'menu_class'      => 'menu',
    'menu_id'         => ,
    'echo'            => true,
    'fallback_cb'     => 'wp_page_menu',
    'before'          => ,
    'after'           => ,
    'link_before'     => ,
    'link_after'      => ,
    'items_wrap'      => '<ul id=\"%1$s\" class=\"%2$s\">%3$s</ul>',
    'depth'           => 0,
    'walker'          =>
);
?>