code: @Override
    public void reset () throws IOException
    {
      _ensureOpen ();
      if (m_nMarkedChar < 0)
        throw new IOException (m_nMarkedChar == INVALIDATED ? "Mark invalid" : "Stream not marked");
      m_nNextCharIndex = m_nMarkedChar;
      m_bSkipLF = m_bMarkedSkipLF;
    }
docs: Resets the stream to the most recent mark.
  
  @exception IOException
  If the stream has never been marked, or if the mark has been
  invalidated