class RandomAccessFileInputStream extends InputStream {

  @Override
  public void mark(int readlimit) {
    try {
      mark = raf.getFilePointer();
    } catch (IOException e) {
      throw new RuntimeException(e);
    }
  }

  public  RandomAccessFileInputStream(File file);
  public  RandomAccessFileInputStream(File file, long rangeOffset, long rangeLength);

}