static void Main(string[] args)
        {
            Arbol <int> myArbol = new Arbol <int>(20,
                                                  new Arbol <int>(4,
                                                                  new Arbol <int>(10),
                                                                  new Arbol <int>(15,
                                                                                  new Arbol <int>(-1,
                                                                                                  new Arbol <int>(-5),
                                                                                                  new Arbol <int>(11),
                                                                                                  new Arbol <int>(3,
                                                                                                                  new Arbol <int>(-9,
                                                                                                                                  new Arbol <int>(14)))))),
                                                  new Arbol <int>(30),
                                                  new Arbol <int>(-22),
                                                  new Arbol <int>(25,
                                                                  new Arbol <int>(17,
                                                                                  new Arbol <int>(4),
                                                                                  new Arbol <int>(14),
                                                                                  new Arbol <int>(2),
                                                                                  new Arbol <int>(-11)),
                                                                  new Arbol <int>(-8),
                                                                  new Arbol <int>(7,
                                                                                  new Arbol <int>(13,
                                                                                                  new Arbol <int>(40)),
                                                                                  new Arbol <int>(33))));

            Iterador <int> miIterador = new Iterador <int>();
            int            nivel      = 0;

            foreach (IEnumerable <int> nodos in miIterador.IteradorAloAncho(myArbol, ValoresPositivos))
            {
                Console.WriteLine("Nivel {0}", nivel);
                foreach (int k in nodos)
                {
                    Console.Write("{0} ", k);
                }
                Console.WriteLine();
                nivel++;
            }
        }