output: #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();
      }
input: #vulnerable code 
                                  public void close() {
          doClose(lbProxyBean, protobufRpcProxyList);
          super.close();
      } 
                              #location 2 
                              #vulnerability type THREAD_SAFETY_VIOLATION