Make a class design for an airport-control-system simulation. Use CRC cards and scenarios. Here is a description of the system: The program is an airport simulation system. For our new airport, we need to know whether we can operate with two runways or whether we need three. The airport works as follows: There are multiple runways. Planes take off and land on runways. Air traffic controllers coordinate the traffic and give planes permission to take off or land. The controllers sometimes give permission right away, but sometimes they tell planes to wait. Planes must keep a certain distance from one another. The purpose of the program is to simulate the airport in operation.