partial         void CopyExtraPropertiesToClone(PickListValue clone, bool includeLocalProperties);
 public PickListValue Clone(bool includeLocalProperties)
 {
     var c = new PickListValue
             {
                 add = add,
                 remove = remove,
                 set = set,
             };
     CopyExtraPropertiesToClone(c, includeLocalProperties);
     return c;
 }