/**
  * Closing this Readtransaction.
  *
  * @throws TTIOException if the closing to the persistent storage fails.
  */
 public boolean close() throws TTIOException {
   if (!mClose) {
     mSession.deregisterBucketTrx(this);
     mBucketReader.close();
     mClose = true;
     return true;
   } else {
     return false;
   }
 }