code: private static boolean waitTillNoNotifications(Environment env, TableRange range)
        throws TableNotFoundException {
      boolean sawNotifications = false;
      long retryTime = MIN_SLEEP_MS;
  
      log.debug("Scanning tablet {} for notifications", range);
  
      long start = System.currentTimeMillis();
      while (hasNotifications(env, range)) {
        sawNotifications = true;
        long sleepTime = Math.max(System.currentTimeMillis() - start, retryTime);
        log.debug("Tablet {} had notfications, will rescan in {}ms", range, sleepTime);
        UtilWaitThread.sleep(sleepTime);
        retryTime = Math.min(MAX_SLEEP_MS, (long) (retryTime * 1.5));
        start = System.currentTimeMillis();
      }
  
      return sawNotifications;
    }
docs: Wait until a range has no notifications.
  
  @return true if notifications were ever seen while waiting