How to unit test akka parent actors when using play InjectedActorSupport.

Code sample:

"cut" must {
    "create new context and forward message" in {
      val id = "key"
      val message = Message(id)
      val cut = system.actorOf(Props(classOf[Parent], factory))
    
      cut ! message
    
      expectMsg(message)
      cut ! PoisonPill
    }
}