Singleton PDO Class, needs PHP 5.3

PDO_Singleton.php

<?php

class PDO_Singleton {

    private static $instance;

    public static function getInstance() {
        if (!(self::$instance instanceof PDO)) {
            self::$instance = new PDO('mysql:dbname=test;host=127.0.0.1', 'root', 'root', array(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION));
        }

        return self::$instance;
    }

    final public static function __callStatic($method, $arguments) {
        return call_user_func_array(array(self::getInstance(), $method), $arguments);
    }

    final private function __construct() {

    }

    final private function __clone() {
        
    }

}

try {
    $result = PDO_Singleton::query('SELECT email, password FROM users')->fetchAll(PDO::FETCH_OBJ);
} catch (Exception $exc) {
    echo $exc->getMessage();
}

var_dump($result);