class ChainedHostResolver implements AdvancedHostResolver {

    @Override
    public Collection<String> getOriginalHostnames(String remappedHost) {
        readLock.lock();
        try {
            if (resolvers.isEmpty()) {
                return emptyList();
            } else {
                return resolvers.get(0).getOriginalHostnames(remappedHost);
            }
        } finally {
            readLock.unlock();
        }
    }

    public  ChainedHostResolver(Collection<? extends AdvancedHostResolver> resolvers);

}