function initializeConfig(&$config)
    {
        if (!isset($GLOBALS['_PEAR_INSTALLER_ROLES'])) {
            PEAR_Installer_Role::registerRoles();
        }

        foreach ($GLOBALS['_PEAR_INSTALLER_ROLES'] as $class => $info) {
            if (!$info['config_vars']) {
                continue;
            }

            $config->_addConfigVars($class, $info['config_vars']);
        }
    }