#vulnerable code 
                                public void close() {
        doClose(lbProxyBean, protobufRpcProxyList);
        super.close();
    } 
                            #location 2 
                            #vulnerability type THREAD_SAFETY_VIOLATION
#fixed code
                                public void close() {
        Collection<List<ProtobufRpcProxy<T>>> values = protobufRpcProxyListMap.values();
        for (List<ProtobufRpcProxy<T>> list : values) {
            doClose(null, list);
        }

        Collection<LoadBalanceProxyFactoryBean> lbs = lbMap.values();
        for (LoadBalanceProxyFactoryBean loadBalanceProxyFactoryBean : lbs) {
            doClose(loadBalanceProxyFactoryBean, null);
        }
        super.close();
    }