/**
  * Execute another future operation on failure
  */
def recoverWith(): Unit = {
  val f: Future[String] = downloadBlob("ftp://blobs/8671").recoverWith {
    case e =>
      println(s"fail download, ${e.getMessage}")
      Future {
        "empty blob"
      }
  }
  println(Await.result(f, 10.seconds))
}

/*
 * output
fail download, invalid uri
empty blob
*/