public function get_all() {
		global $wpdb;

		return $wpdb->get_col(
			$wpdb->prepare(
				"SELECT cp.ID FROM $wpdb->posts cp
	                    LEFT JOIN $wpdb->posts rp ON rp.ID = cp.post_parent
						WHERE cp.post_type LIKE %s
						  AND cp.post_status LIKE %s
						  AND rp.post_status LIKE %s LIMIT 1",
				'uo-closure',
				'publish',
				'publish'
			)
		);
	}