clone.m_exprObj = (XNodeSet) m_exprObj.clone();
clone.m_exprObj = (XNodeSet) m_exprObj.cloneWithReset();
  public Object clone() throws CloneNotSupportedException  {    FilterExprWalker clone = (FilterExprWalker) super.clone();    // clone.m_expr = (Expression)((Expression)m_expr).clone();    if (null != m_exprObj)      clone.m_exprObj = (XNodeSet) m_exprObj.clone();    return clone;  }