@Override
        public void updateProviders(ProviderGroup providerGroup) {
            ps.clear();
            ps.put(providerGroup.getName(), providerGroup.getProviderInfos());
            if (countDownLatch != null) {
                countDownLatch.countDown();
            }
        }
@author <a href=mailto:orezsilence@163.com>zhangchengxi</a>
registry/registry-local/src/test/java/com/alipay/sofa/rpc/registry/local/DomainRegistryTest.java