你好：
我有一个疑问，当Registry调用destroy后不会去清除AbstractRegistryFactory中的缓存，导致以同样的参数再次获取的时候得到了一个已经无法使用的Registry。这个时设计的时候就认为不该这么使用吗？
.setPath(RegistryService.class.getName())
                .addParameter(INTERFACE_KEY, RegistryService.class.getName())
                .removeParameters(EXPORT_KEY, REFER_KEY)
                .build();
        String key = url.toServiceStringWithoutResolving();
        
        LOCK.lock();
        try {
            Registry registry = REGISTRIES.get(key);
            if (registry != null) {
                return registry;
            }
            
            registry = createRegistry(url);
            if (registry == null) {
                throw new IllegalStateException("Can not create registry " + url);
            }
            REGISTRIES.put(key, registry);
            return registry;
        } finally {
            
            LOCK.unlock();
        }
    }
    protected abstract Registry createRegistry(URL url);
    private static Registry DEFAULT_NOP_REGISTRY = new Registry() {
        @Override
        public URL getUrl() {
            return null;
        }