static void Main(string[] args)
{
// prepared stage
var invoker = new Invoker();
var commanderA = new CommanderA();
var commanderB = new CommanderB();
// receiver order
var order1 = new CommandOrderA(commanderA);
var order2 = new CommandOrderB(commanderB);
var order3 = new CommandOrderA(commanderA);
invoker.ReceiveOrder(order1);
invoker.ReceiveOrder(order2);
invoker.ReceiveOrder(order3);
invoker.CancelOrder(order3);
invoker.NodifyCommander();
}