public VisitorPattern()
        {
            var concreteElementB = new ConcreteElementB();
            concreteElementB.Accept(new ConcreteVisitor());

            var concreteElementA = new ConcreteElementA();
            concreteElementA.Accept(new ConcreteVisitor());
        }
 public abstract void Visit(ConcreteElementB me);
 public override void Visit(ConcreteElementB me)
 {
     Console.WriteLine("ConcreteElementB");
 }