     }
     
     func open() {
-        print("elevator: \(id) opening doors at floor: \(floor)")
+        print("elevator: \(short_id()) opening doors at floor: \(floor)")
     }
     
     func close() {
-        print("elevator: \(id) closing doors at floor: \(floor)")
+        print("elevator: \(short_id()) closing doors at floor: \(floor)")
    }
     
     func arriveAtFloor() {

    }
}

class Building {
    var floors: Int
    let control: Control = Control()
    var elevators = [Elevator]()

    init(floors: Int) {
        self.floors = floors
        print(description())
        elevators.append(Elevator(maxWeight: 1200, maxFloor: self.floors, control: self.control))
        for elevator in elevators {

    let dispatchQueue: DispatchQueue = DispatchQueue(label: "com.orens.elevator.elevator")
    
    init(maxWeight: Double, maxFloor: Int, control: Control) {
        self.maxWeight = maxWeight
        self.maxFloor = maxFloor
        self.control = control
        super.init()
        print(description())
    }
    
