=clu #18345 Support local address in cluster commands

* and clarify the doc sample for leave

akka-docs/rst/scala/cluster-usage.rst

@@ -152,7 +152,9 @@ above.
 
 A more graceful exit can be performed if you tell the cluster that a node shall leave.
 This can be performed using :ref:`cluster_jmx_scala` or :ref:`cluster_command_line_scala`.
-It can also be performed programmatically with ``Cluster(system).leave(address)``.
+It can also be performed programmatically with:
+
+.. includecode:: code/docs/cluster/ClusterDocSpec.scala#leave
 
 Note that this command can be issued to any member in the cluster, not necessarily the
 one that is leaving. The cluster extension, but not the actor system or JVM, of the 

akka-docs/rst/scala/code/docs/cluster/ClusterDocSpec.scala

@@ -0,0 +1,27 @@
+/**
+ * Copyright (C) 2015 Typesafe Inc. <http://www.typesafe.com>
+ */
+package docs.cluster
+
+import akka.cluster.Cluster
+import akka.testkit.AkkaSpec
+
+object ClusterDocSpec {
+
+  val config =
+    """
+    akka.actor.provider = "akka.cluster.ClusterActorRefProvider"
+    akka.remote.netty.tcp.port = 0
+    """
+}
+
+class ClusterDocSpec extends AkkaSpec(ClusterDocSpec.config) {
+
+  "demonstrate leave" in {
+    //#leave
+    val cluster = Cluster(system)
+    cluster.leave(cluster.selfAddress)
+    //#leave
+  }
+
+}