MyFirst Akka Actor written in Scala

FirstActor

import akka.actor._
import akka.pattern.ask
import akka.util.duration._
import akka.util.Timeout
import akka.dispatch.Await

case class PlayerAddRequest(name: String)

class PlayerBuffer extends Actor {

  var players = Set.empty[String]

  def receive = {
    case PlayerAddRequest(name) => {
      if (players.size < 6) {
        println("added " + name)
        players = players.+(name)
        println(players.size)
      } else {
        println("max players added")
        System.exit(1)
      }
    }
  }
}

object FirstAkkaRun extends App {
  val as = ActorSystem("PlayerAddSystem")
  val playerBuff = as.actorOf(Props[PlayerBuffer], "playert")
  implicit val timeout = Timeout(5 minutes)
  val future = playerBuff ? PlayerAddRequest("pras")
  println(Await.result(future, timeout.duration).asInstanceOf[String])
}