カスタム投稿タイプのシングルページが表示された時に任意のカスタムメニューにcurrent-menu-itemのクラスを追加する処理

gistfile1.php

<?php
function add_nav_menu_custom_class( $menu_items ) {
 
	$lists = array(
		'post_type1' => 'page_slug1',
		'post_type2' => 'page_slug2',
		'post_type3' => 'page_slug3',
		'post_type4' => 'page_slug4',
		'post_type5' => 'page_slug5',
		'post_type6' => 'page_slug6',
		'post_type7' => 'page_slug7',
	);
    
    $current_post_type = get_post_type();
	
	foreach($lists as $post_type => $page_slug){
	
		if($current_post_type==$post_type){
			foreach ( $menu_items as $menu_key => $menu_item ) {
				if(get_page($menu_item->object_id)->post_name == $page_slug){
					$menu_items[$menu_key]->classes[] = 'current-menu-related'; //任意のクラス名
				}
			}
		}
	}
	return $menu_items;
}
add_filter( 'wp_nav_menu_objects', 'add_nav_menu_custom_class' );

?>