#vulnerable code 
                                public WebDriverManager useTaobaoMirror(String taobaoUrl) {
        driverUrl = getUrl(taobaoUrl);
        return instance;
    } 
                            #location 3 
                            #vulnerability type THREAD_SAFETY_VIOLATION
#fixed code
                                public WebDriverManager useTaobaoMirror(String taobaoUrl) {
        driverUrl = getUrl(taobaoUrl);
        return instanceMap.get(driverManagerType);
    }