class Singleton { private static $instance; private function __construct() {} public static function getInstance() { if(!isset(self::$instance)) { self::$instance = new Singleton(); } return self::$instance; } } $singleton1 = Singleton::getInstance(); $singleton2 = Singleton::getInstance(); var_dump($singleton1 === $singleton2); // trueThis code creates a Singleton class with a private constructor and a private static instance variable. The getInstance() method checks if an instance of the class has already been created, and if not, it creates a new instance. The same instance is returned each time getInstance() is called. The package library for this code is likely the core PHP library, as the getInstance() method is a widely-used design pattern.