Iterator Composite pattern example

public class MyDiner{

    private string[] _menuitems;
    private int _position;
    private IEnumerable<string> _subMenu;

    public MyDiner(ICollection<string> subMenu) : IEnumerable{
        _position = 0;
        _menuItems = new string[] {"Coffee", "Latte machiato", "Cappuchino"};
        _submenu = submenu.Iterator();
    }


    public bool HasNext(){
        return _submenu.HasNext();
    }


    public string Next(){
        if(_position < _menuitems.length){
            _position ++;
            return = __menuItems[_position - 1];
        }
        else if(_submenu.HasNext()){
            return _submenu.Next();
        }
        else {
            thow new IllegalOperationException("I'm out of elements!");
        }
    }



}