This task can not be completed using code that works in an XCode Playground.

class Point {
  var x: Int
  var y: Int

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

class Machine {
  var location: Point

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

  func move(_ direction: String) {
    print("Do nothing! Im a machine!")
  }
}

// Enter your code below

class Robot: Machine {
    override func move(_ direction: String) {
        switch _ direction {
        case "Up":
            self.location = (Point(x: 0, y: 1))
        case "Down":
            self.location = (Point(x: 0, y: -1))
        case "Left":
            self.location = (Point(x: -1, y: 0))
        case "Right":
            self.location = (Point(x: 1, y: 0))
        default: break
        }
    }
}