The following entity types shall be part of this design:  ElevatorCar (which the passengers ride in)  ElevatorDoor (opens and closes)  CallButton (on each floor to request an elevator)  SelectFloorButton (in the elevator car, one for each floor)  EmergencyButton (in elevator, rings buzzer if elevator gets stuck)  Controller (which controls all the actions)  Buzzer  Elevator Requests Queue. You are to turn in the use case diagram, the associated scenarios for each use case, the class diagram, and the interaction (sequence) diagram.