partial         void CopyExtraPropertiesToClone(User clone, bool includeLocalProperties);
 public User Clone(bool includeLocalProperties)
 {
     var c = new User
             {
                 DisplayName = DisplayName,
                 Email = Email,
                 Enabled = Enabled,
                 FirstName = FirstName,
                 Id = Id,
                 IsExternal = IsExternal,
                 LastLogIn = LastLogIn,
                 LastName = LastName,
                 Phone = Phone,
                 UserName = UserName,
                 Groups = Groups.Select(x=>x.Clone(includeLocalProperties)).ToList(),
             };
     CopyExtraPropertiesToClone(c, includeLocalProperties);
     return c;
 }