code: @Override
    public void seek(long pos) throws IOException {
      int n = (int) (real_pos - pos);
      if (n >= 0 && n <= buf_end) {
        buf_pos = buf_end - n;
      } else {
        super.seek(pos);
        invalidate();
      }
    }
docs: Moves the internal pointer to the passed (byte) position in the file.
  
  @param pos The byte position to move to.