如何将父帖子添加到自定义帖子类型？

我找到了一个例子：

function codex_custom_init() {
// Our People
$people_label = array(
    \'name\' => \'People\',
    \'singular_name\' => \'People\',
    \'add_new\' => \'Add People\',
    \'add_new_item\' => \'Add New People\',
    \'edit_item\' => \'Edit People\',
    \'new_item\' => \'New People\',
    \'all_items\' => \'All People\',
    \'view_item\' => \'View People\',
    \'search_items\' => \'Search People\',
    \'not_found\' => \'No People found\',
    \'not_found_in_trash\' => \'No People found in Trash\',
    \'parent_item_colon\' => \'\',
    \'menu_name\' => \'People\',
);
$people_args = array (
    \'labels\' => $people_label,
    \'public\' => true,
    \'publicly_queryable\' => true,
    \'show_ui\' => true,
    \'show_in_menu\' => true,
    \'query_var\' => true,
    \'rewrite\' => array( \'slug\' => \'our-people\'),
    \'capability_type\' => \'page\',
    \'has_archive\' => true,
    \'hierarchical\' => true,
    \'menu_position\' => null,
    \'menu_icon\' => get_template_directory_uri() . \'/images/icons/people.png\',
    \'supports\' => array(\'title\', \'editor\', \'author\', \'thumbnail\', \'excerpt\',\'page-attributes\'),
);

register_post_type(\'people\', $people_args);}