public override void Update(object destObject = null)
        {
            var actualGroups = Model.GetGroups();

            foreach (var group in AllGroups)
            {
                if (GroupMember.Contains(group) && !actualGroups.Contains(group.Model))
                {
                    Model.GroupAdd(group.Model);
                }
                if (!GroupMember.Contains(group) && actualGroups.Contains(group.Model))
                {
                    Model.GroupRemove(group.Model);
                }
            }
            base.Update(destObject);
            Model.Save();
        }