#vulnerable code 
                                protected Optional<String> handleCache(Architecture arch, String version,
            String os, boolean getLatest, boolean cache) {
        Optional<String> driverInCache = empty();
        if (cache || !getLatest) {
            driverInCache = getDriverFromCache(version, arch, os);
        }
        if (!version.isEmpty()) {
            versionToDownload = version;
        }
        return driverInCache;
    } 
                            #location 8 
                            #vulnerability type THREAD_SAFETY_VIOLATION
#fixed code
                                protected Optional<String> handleCache(Architecture arch, String version,
            String os, boolean getLatest, boolean cache) {
        Optional<String> driverInCache = empty();
        if (cache || !getLatest) {
            driverInCache = getDriverFromCache(version, arch, os);
        }
        if (!version.isEmpty()) {
            storeVersionToDownload(version);
        }
        return driverInCache;
    }