DOC: Update Durable Mailboxes Chapter. See #1472

akka-docs/modules/code/akka/docs/actor/mailbox/DurableMailboxDocSpec.scala

@@ -0,0 +1,31 @@
+package akka.docs.actor.mailbox
+
+//#imports
+import akka.actor.Actor
+import akka.actor.Props
+import akka.actor.mailbox.FileDurableMailboxType
+
+//#imports
+
+import org.scalatest.{ BeforeAndAfterAll, WordSpec }
+import org.scalatest.matchers.MustMatchers
+import akka.testkit.AkkaSpec
+
+class MyActor extends Actor {
+  def receive = {
+    case x ⇒
+  }
+}
+
+class DurableMailboxDocSpec extends AkkaSpec {
+
+  "define dispatcher with durable mailbox" in {
+    //#define-dispatcher
+    val dispatcher = system.dispatcherFactory.newDispatcher(
+      "my-dispatcher", throughput = 1, mailboxType = FileDurableMailboxType).build
+    val myActor = system.actorOf(Props[MyActor].withDispatcher(dispatcher), name = "myactor")
+    //#define-dispatcher
+    myActor ! "hello"
+  }
+
+}