<?php

class Registry {
    protected static $data = array();

    // this is a static class
    final private function __construct()
    {

    }

    public static function set($key, $value)
    {
        self::$data[$key] = $value;
    }

    public static function get($key, $default = NULL)
    {
        if (isset(self::$data[$key])) {
            return self::$data[$key];
        } else {
            return $default;
        }
    }
}