code: public static long getTxIfoCacheTimeout(FluoConfiguration conf, TimeUnit tu) {
      long millis = conf.getLong(TX_INFO_CACHE_TIMEOUT, TX_INFO_CACHE_TIMEOUT_DEFAULT);
      if (millis <= 0) {
        throw new IllegalArgumentException("Timeout must positive for " + TX_INFO_CACHE_TIMEOUT);
      }
      return tu.convert(millis, TimeUnit.MILLISECONDS);
    }
docs: Gets the time before stale entries in the cache are evicted based on age. This method returns a
  long representing the time converted from the TimeUnit passed in.
  
  @param conf The FluoConfiguration
  @param tu The TimeUnit desired to represent the cache timeout