ecshop中初始化会员数据调整类的unserialize()的疑问

/**<br /> * 初始化会员数据整合类<br /> *<br /> * @access  public<br /> * @return  object<br />*/<br />function &init_users()<br />{<br />    $set_modules = false;<br />    static $cls = null;<br />    if ($cls != null)<br />    {<br />        return $cls;<br />    }<br />    include_once(ROOT_PATH . 'includes/modules/integrates/' . $GLOBALS['_CFG']['integrate_code'] . '.php');<br />    $cfg = unserialize($GLOBALS['_CFG']['integrate_config']);<br />    $cls = new $GLOBALS['_CFG']['integrate_code']($cfg);<br /><br />    return $cls;<br />}