I am really trying to figure out what's happening

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! I am a machine!")
  }
}

// Enter your code below
class Robot: Machine {
    override func move(direction: String) {
        switch direction {
            case "Up": self.location.y += 1
            case "Down": self.location.y -= 1
            case "Right": self.location.x += 1
            case "Left": self.location.x -= 1
        default: print("Do nothing") // Or you could put a break clause per the instructions
        }
    }
}