public GroupViewModel(Group group, GroupViewModel parent)
{
_group = group;
_parent = parent;
_children = new ReadOnlyCollection<GroupViewModel>(
(from child in _group.SubGroups select new GroupViewModel(child, this)).ToList()
);
}
public void AddGroupMembership(GroupViewModel model)
{
_user.AddGroupMembership(model.Name);
OnPropertyChanged("Membership");
}