Consider a class called Building. This class consists of a number of floors (numberOfFloors) for the building, a current floor for the elevator (current), a requested floor of a person waiting for the elevator (requestedFloor), and methods for constructing the building object, for moving the elevator one floor up, for moving the elevator one floor down, for requesting the elevator and for starting the elevator going. Assume that requestedFloor will be set to 0 if there are currently no requests being made (or the last request has already been fulfilled).

Refer to Class Definition Ch 04-3: What visibility modifiers would you use for the methods that move the elevator up one floor, move the elevator down one floor, that request the elevator, and that start the elevator moving?