move code to src/test

* so that it compiles and tests pass
* fix some additional snip references in getting started

akka-docs/src/test/java/jdocs/persistence/PersistenceEventAdapterDocTest.java

@@ -0,0 +1,32 @@
+/*
+ * Copyright (C) 2015-2017 Lightbend Inc. <http://www.lightbend.com>
+ */
+
+package jdocs.persistence;
+
+import akka.persistence.journal.EventAdapter;
+import akka.persistence.journal.EventSeq;
+
+public class PersistenceEventAdapterDocTest {
+
+  @SuppressWarnings("unused")
+  static
+  //#identity-event-adapter
+  class MyEventAdapter implements EventAdapter {
+    @Override
+    public String manifest(Object event) {
+      return ""; // if no manifest needed, return ""
+    }
+
+    @Override
+    public Object toJournal(Object event) {
+      return event; // identity
+    }
+
+    @Override
+    public EventSeq fromJournal(Object event, String manifest) {
+      return EventSeq.single(event); // identity
+    }
+  }
+  //#identity-event-adapter
+}