From 914a94e40524d4232ee5a0da6570f531c5252d9b Mon Sep 17 00:00:00 2001
From: Jorge Gomez <gomezjorge.exequiel@gmail.com>
Date: Wed, 31 Mar 2021 04:14:12 -0300
Subject: [PATCH] ActorSinkWithAckExample Ack message (#30127)

Using the example does not work in Java, because it seems that `Sink` compares by equality, no by class.
---
 .../docs/akka/stream/typed/ActorSinkWithAckExample.java    | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/akka-stream-typed/src/test/java/docs/akka/stream/typed/ActorSinkWithAckExample.java b/akka-stream-typed/src/test/java/docs/akka/stream/typed/ActorSinkWithAckExample.java
index 9eeacbf8a4..5888eb07f5 100644
--- a/akka-stream-typed/src/test/java/docs/akka/stream/typed/ActorSinkWithAckExample.java
+++ b/akka-stream-typed/src/test/java/docs/akka/stream/typed/ActorSinkWithAckExample.java
@@ -17,7 +17,9 @@ public class ActorSinkWithAckExample {
 
   // #actor-sink-ref-with-backpressure
 
-  class Ack {}
+  enum Ack {
+    INSTANCE;
+  }
 
   interface Protocol {}
 
@@ -58,7 +60,6 @@ public class ActorSinkWithAckExample {
     final ActorRef<Protocol> actorRef = // spawned actor
         null; // #hidden
 
-    final Ack ackMessage = new Ack();
     final Complete completeMessage = new Complete();
 
     final Sink<String, NotUsed> sink =
@@ -66,7 +67,7 @@ public class ActorSinkWithAckExample {
             actorRef,
             (responseActorRef, element) -> new Message(responseActorRef, element),
             (responseActorRef) -> new Init(responseActorRef),
-            ackMessage,
+            Ack.INSTANCE,
             completeMessage,
             (exception) -> new Fail(exception));