Design a system that represents a bike kiosk.
Must have methods for

• checking out a bike
• checking in a bike
• listing inventory

Kiosk has 10 slots...
there is only one kiosk (to start)
to initialize or start you kiosk, you need it with 10 bikes
checkout a bike, could be a random one,
check in a bike, and it needs a slot or port (thats empty, otherwise raise an exception)
method for listing number of available ports...
method to report that a bike is in need of maintenance