I have no clue why this code wont satisfy the challenge, error, you need to provide an implementation for the move metho

class Point {
    var x: Int
    var y: Int

    init(x: Int, y: Int) {
        self.x = x
        self.y = y
    }
}

enum Direction {
    case left
    case right
    case up
    case down
}

class Robot {
    var location: Point

    init(location: Point) {
        self.location = Point(x: 0, y: 0)
    }

   func move(direction: Direction) {
        // Enter your code below
        switch direction {
        case .Up:
            return location.y += 1
        case .Down:
            return location.y -= 1
        case .Right:
            return location.x += 1
        default:
            return location.x -= 1
        }
    }
}

let newRobot = Robot()
newRobot.move(direction up)