TreeView Multibinding with multiple classes

Question

I was reading this post StackOverFlowPost but I think I need more than that. Here is my situation. I am trying to fill a TreeView with items from a class with two different types ObservableCollection's. Here is the class definition:

public class User : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;
    public void OnPropertyChanged(PropertyChangedEventArgs e)
    {
        if (PropertyChanged != null)
            PropertyChanged(this, e);
    }
    private string _Username;
    public string Username
    {
        get { return this._Username; }
        set
        {
            this._Username = value;
            OnPropertyChanged(new PropertyChangedEventArgs("Username"));
        }
    }
    private ObservableCollection<Computer> _UserComputers;
    public ObservableCollection<Computer> UserComputers
    {
        get { return this._UserComputers; }
        set
        {
            this._UserComputers = value;
            OnPropertyChanged(new PropertyChangedEventArgs("UserComputers"));
        }
    }
    private ObservableCollection<CellPhone> _UserCellPhones;
    public ObservableCollection<CellPhone> UserCellPhones
    {
        get { return this._UserCellPhones; }
        set
        {
            this._UserCellPhones = value;
            OnPropertyChanged(new PropertyChangedEventArgs("UserCellPhones"));
        }
    }
    public User()
    {
        this.UserComputers = new ObservableCollection<Computer>();
        this.UserCellPhones = new ObservableCollection<CellPhone>();
    }

}

I would like the TreeView to look like the following:

• Brian
• (child)Computer
• (child)CellPhone

Every example I can find only shows how to fill a TreeView with the Class->Class->Class->Properties Association format. I would like to do a Class->2Classes->Properties format.

Any help would be greatly appreciated. Thanks,

-Brian