foo.scala

  object HouseBuilderAsync1 {
    def circumference(d: Double): Future[Double] = Math.piSlow.map { _  * d }
    def buildWindow(c: Double): Window = Window(c)
    def buildHouse(window: Window): House = House(window)
  }
  object HouseControllerAsync1 {
    import HouseBuilderAsync._
    circumference(10).map(buildWindow).map(buildHouse)
    // scala.concurrent.Future[AsynsVsSync.House] = Success(House(Window(31.400000000000002)))
  }