Singleton via the `new` operator from outside of this class. */ protected function __construct() { } /** * Restituisce l'istanza della classe in oggetto. * * @return Singleton */ public static function getInstance() { $class = get_called_class(); if (!isset(self::$instance[$class])) { self::$instance[$class] = new static(); } return self::$instance[$class]; } /** * Private clone method to prevent cloning of the instance of the Singleton instance. */ private function __clone() { } /** * Private unserialize method to prevent unserializing of the Singleton instance. */ private function __wakeup() { } }