There is a Parking lot: which has 20 Parking spots And assume only there are three types of vehicles, which are main.java.parkingLot.models.Bike, Car, Bus Bike needs 1 spots Car need 2 spots Bus needs 4 Spots When ever some vehicles comes, before parking, it has to check is there any free spot, and can it park there or not based on its size Parking lot has to keep track of the number of spots whenever vehicles parks and unparks