@Override
 public DateTime getMaxTime() {
   final IndexedLongs timestamps = index.getReadOnlyTimestamps();
   final DateTime retVal = new DateTime(timestamps.get(timestamps.size() - 1));
   Closeables.closeQuietly(timestamps);
   return retVal;
 }
 @Override
 public boolean withinBounds() {
   return baseOffset.withinBounds() && timestamps.get(baseOffset.getOffset()) < threshold;
 }