A proper way to make a Future-wait (sleep) with Akka

good-wait.scala

import akka.actor.ActorSystem
import akka.pattern.Patterns.after
import scala.concurrent.duration._

val as = ActorSystem()

val x = after(2.seconds, as.scheduler, global, Future.successful(1)).flatMap { _ =>
  Future {
    // long operation that _starts_ after the delayed future completes
    1
  }
}