copy.m_DateFormat = m_DateFormat;
  public Object copy() {    Attribute copy = new Attribute(m_Name);    copy.m_Index = m_Index;    /*    if (!isNominal() && !isString())      return copy;    */    copy.m_Type = m_Type;    copy.m_Values = m_Values;    copy.m_Hashtable = m_Hashtable;     return copy;  }