@Override
        public void removeProvider(ProviderGroup providerGroup) {
            for (ProviderInfo providerInfo : providerGroup.getProviderInfos()) {
                ps.remove(providerInfo.getHost() + ":" + providerInfo.getPort());
            }
            if (countDownLatch != null) {
                countDownLatch.countDown();
            }
        }
Sets count down latch.

@param countDownLatch the count down latch
registry/registry-nacos/src/test/java/com/alipay/sofa/rpc/registry/nacos/NacosRegistryTest.java