我正在学习Akka，并编写了下面的代码来限制发送到TradeAction演员的消息数量。每秒最多发送3条消息。可以修改限制器以设置每条消息之间的时间吗？例如，在message1和message2之间延迟2秒，在message2和message3之间延迟1秒。

import akka.NotUsed
import akka.actor.{Actor, ActorRef, ActorSystem, Props}
import akka.stream.{ActorMaterializer, OverflowStrategy}
import akka.stream.scaladsl.{Sink, Source}
import systemconfig.ActorSystemConfig

import scala.concurrent.duration.DurationInt

case class Action(side: String)

object PlaceTrade {

  val actorSystem = ActorSystem("firstActorSystem")
  println(actorSystem.name)

  object TradeAction {
    def props(action : String) = Props(new TradeAction(action))
  }

  class TradeAction(actorName: String) extends Actor {
    override def receive: Receive = {
      case "Buy" => {
        val r = requests.get("http://www.google.com")
        println("r status code is "+r.statusCode)
        println("Buy")
        println("")
      }
      case "Sell" => {
        val r = requests.get("http://www.google.com")
        println("r status code is "+r.statusCode)
        println("Sell")
        println("")
      }
      case _ =>
    }
  }

  implicit val materializer = ActorMaterializer.create(ActorSystemConfig.getActorSystem)

  def getThrottler(ac: ActorRef) = Source.actorRef(bufferSize = 1000, OverflowStrategy.dropNew)
    .throttle(1, 3.second)
    .to(Sink.actorRef(ac, NotUsed))
    .run()

  def main(args: Array[String]): Unit = {
    val tradeAction = actorSystem.actorOf(TradeAction.props("TradeAction"))
    val throttler = getThrottler(tradeAction)

    val l = List(Action("Buy"),Action("Buy"),Action("Buy"),Action("Sell"))
    l.foreach(action => {
      throttler ! action.side
    })
  }

}