static void CalculateArea(IAmVisitable visitable)
{
var visitor = new AreaCalculationVisitor();
visitable.Accept(visitor);
Console.WriteLine("{0} area: {1}", visitable.GetType().Name, visitor.Area);
}
static void CalculateTotalArea(IEnumerable <IAmVisitable> visitables)
{
var visitor = new AreaCalculationVisitor();
foreach (var visitable in visitables)
{
visitable.Accept(visitor);
}
Console.WriteLine("Total area: {0}", visitor.Area);
}