@AfterClass
    public static void after() {
        if (OLD_VALUE_SHUTDOWN_WAIT_KEY == null) {
            System.clearProperty(CommonConstants.SHUTDOWN_WAIT_KEY);
        } else {
            System.setProperty(CommonConstants.SHUTDOWN_WAIT_KEY, OLD_VALUE_SHUTDOWN_WAIT_KEY);
        }

        if (OLD_VALUE_DUBBO_CONFIG_IGNORE_DUPLICATED_INTERFACE == null) {
            System.clearProperty(ConfigKeys.DUBBO_CONFIG_IGNORE_DUPLICATED_INTERFACE);
        } else {
            System.setProperty(ConfigKeys.DUBBO_CONFIG_IGNORE_DUPLICATED_INTERFACE,
                OLD_VALUE_DUBBO_CONFIG_IGNORE_DUPLICATED_INTERFACE);
        }

        if (OLD_VALUE_DUBBO_CONFIG_MODE == null) {
            System.clearProperty(ConfigKeys.DUBBO_CONFIG_MODE);
        } else {
            System.setProperty(ConfigKeys.DUBBO_CONFIG_MODE, OLD_VALUE_DUBBO_CONFIG_MODE);
        }
    }
@author <a href=mailto:leizhiyuan@gmail.com>leizhiyuan</a>
bootstrap/bootstrap-dubbo/src/test/java/com/alipay/sofa/rpc/bootstrap/dubbo/DubooServerTest.java