Remove samples (#22288)

Add code, that was used for documentation to the appropriate projects
or akka-docs.

akka-remote-tests/src/multi-jvm/scala/akka/remote/sample/MultiNodeSample.scala

@@ -0,0 +1,63 @@
+//#package
+package akka.remote.sample
+
+//#package
+
+//#config
+import akka.remote.testkit.{ MultiNodeConfig, STMultiNodeSpec }
+
+object MultiNodeSampleConfig extends MultiNodeConfig {
+  val node1 = role("node1")
+  val node2 = role("node2")
+}
+//#config
+
+//#spec
+import akka.actor.{ Actor, Props }
+import akka.remote.testkit.MultiNodeSpec
+import akka.testkit.ImplicitSender
+
+class MultiNodeSampleSpecMultiJvmNode1 extends MultiNodeSample
+class MultiNodeSampleSpecMultiJvmNode2 extends MultiNodeSample
+
+object MultiNodeSample {
+  class Ponger extends Actor {
+    def receive = {
+      case "ping" ⇒ sender() ! "pong"
+    }
+  }
+}
+
+class MultiNodeSample extends MultiNodeSpec(MultiNodeSampleConfig)
+  with STMultiNodeSpec with ImplicitSender {
+
+  import MultiNodeSample._
+  import MultiNodeSampleConfig._
+
+  def initialParticipants = roles.size
+
+  "A MultiNodeSample" must {
+
+    "wait for all nodes to enter a barrier" in {
+      enterBarrier("startup")
+    }
+
+    "send to and receive from a remote node" in {
+      runOn(node1) {
+        enterBarrier("deployed")
+        val ponger = system.actorSelection(node(node2) / "user" / "ponger")
+        ponger ! "ping"
+        import scala.concurrent.duration._
+        expectMsg(10.seconds, "pong")
+      }
+
+      runOn(node2) {
+        system.actorOf(Props[Ponger], "ponger")
+        enterBarrier("deployed")
+      }
+
+      enterBarrier("finished")
+    }
+  }
+}
+//#spec