/** {@inheritDoc} */
 @Override
 public void subtract(EntryStatistics le) {
   super.subtract(le);
   if (le instanceof BlockEntryStatistics)
     blockCount -= ((BlockEntryStatistics) le).getBlockCount();
 }
 @Override
 public void write(DataOutput out) throws IOException {
   super.write(out);
   out.writeInt(blockCount);
 }
 /** {@inheritDoc} */
 @Override
 public void add(EntryStatistics le) {
   super.add(le);
   if (le instanceof BlockEntryStatistics)
     blockCount += ((BlockEntryStatistics) le).getBlockCount();
 }
 @Override
 public void readFields(DataInput in) throws IOException {
   super.readFields(in);
   blockCount = in.readInt();
 }