@Override public synchronized void close() throws IOException {
  try {
    if (syncTask != null) {
      syncTask.cancel();
    }
    sync();
    unmapFile();
  }
  finally {
    super.close();
  }
}

@ Override public synchronized void close ( ) throws IOException { try { if ( syncTask != null ) { syncTask . cancel ( ) ; } sync ( ) ; unmapFile ( ) ; } finally { super . close ( ) ; } }
closes the underlying rrd file .
