Singleton

class MySingleton
{
    private static $instance;

    public static function getInstance()
    {
        if (null === self::$instance) {
            self::$instance = new self;
        }

        return self::$instance;
    }

    private function __clone()
    {
    }

    private function __wakeup()
    {
    }

    protected function __construct()
    {
    }
}