#fixed code
                             @Override
	public void close() {
		executorService.shutdown();
	}
#vulnerable code 
                             @Override
	public void close() {
		if (executorService != null) {
			synchronized (InetUtils.class) {
				if (executorService != null) {
					executorService.shutdown();
					executorService = null;
				}
			}
		}
	} 
                            #location 3 
                            #vulnerability type THREAD_SAFETY_VIOLATION