@Override
  public boolean setLength(final int recordId,
                           final long newLength) throws IOException {
    final boolean reallyChanged = getLongField(recordId, RecordLayout.LENGTH_OFFSET) != newLength;
    if (reallyChanged) {
      setLongField(recordId, RecordLayout.LENGTH_OFFSET, newLength);
    }
    return reallyChanged;
  }
@Override
  public boolean setLength(final int recordId,
                           final long newLength)