code: public Calendar getLastUpdateTime() {
          if (null != lastUpdateTime && lastUpdateTime.after(Calendar.getInstance())) {
              LOG.warn("Last update time newer than now {} for {}", lastUpdateTime, owner);
              return null; // Something's broken - we don't know
          }
          return lastUpdateTime;
      }
docs: Returns the last update time estimated from the file update times and clientlib folder create times.
  This is only a lower bound for the update time of the client library including its embedded files.