private int addSizes(final byte[] data) {
    int off = 0;
    if (mySize != null) {
      System.arraycopy(mySize.getBytes(), 0, data, 0, DWORD);
      off += DWORD;
    }
    if (myCompressedSize != null) {
      System.arraycopy(myCompressedSize.getBytes(), 0, data, off, DWORD);
      off += DWORD;
    }
    return off;
  }
private int addSizes(final byte[] data)