code: public void setEmpty ()
    {
      m_sValue = "";
      m_nLeading = 0;
      m_nTrailing = 0;
      m_bIsEmpty = true;
      if (m_aNext != null)
        m_aNext.m_bPrevEmpty = true;
    }
docs: Marks this line empty. Also sets previous/next line's empty attributes.