1<?php
2class Singleton
3{
4    private static $uniqueInstance = null;
5
6    protected function __construct()
7    {
8    }
9
10    final private function __clone()
11    {
12    }
13
14    public static function getInstance()
15    {
16        if (self::$uniqueInstance === null) {
17            self::$uniqueInstance = new self;
18        }
19
20        return self::$uniqueInstance;
21    }
22}
23