#vulnerable code 
                              public static CacheManager get() {
    if (instance == null) {
      synchronized (log) {
        if (instance == null) {
          instance = new CacheManager();
        }
      }
    }
    return instance;
  } 
                            #location 9 
                            #vulnerability type THREAD_SAFETY_VIOLATION
#fixed code
                              public static CacheManager get() {
    return get(defaultCacheManager);
  }