def combineLists[S,T](list: List[Future[Either[S, List[T]]]], result: List[T] = Nil)
    : Future[Either[S, List[T]]] = {
    list match {
      case Nil => Future.successful(Right(result))
      case h :: t => {
        h.flatMap { r =>
          r match {
            case Left(error) => Future.successful(Left(error))
            case Right(l) => combineLists(t, l ++ result)
          }
        }
      }
    }
  }