old-new-wiaas/backend/app/plugins/wiaas/includes/class-wiaas-admin.php

<?php

if ( ! defined( 'ABSPATH' ) ) {
	exit; // Exit if accessed directly
}

class Wiaas_Admin {

	public static function init() {
		require_once dirname( __FILE__ ) . '/admin/package/class-wiaas-admin-package-pricing.php';
		require_once dirname( __FILE__ ) . '/admin/package/class-wiaas-admin-package-addon.php';
		require_once dirname( __FILE__ ) . '/admin/package/class-wiaas-admin-package-option-groups.php';
	}
}

Wiaas_Admin::init();