CR comments

Author: original-brownbear

test/framework/src/main/java/org/elasticsearch/search/ErrorTraceHelper.java

@@ -19,6 +19,8 @@
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.function.BooleanSupplier;
 
+import static org.elasticsearch.test.ESTestCase.asInstanceOf;
+
 /**
  * Utilities around testing the `error_trace` message header in search.
  */
@@ -28,7 +30,7 @@ public enum ErrorTraceHelper {
     public static BooleanSupplier setupErrorTraceListener(InternalTestCluster internalCluster) {
         final AtomicBoolean transportMessageHasStackTrace = new AtomicBoolean(false);
         internalCluster.getDataNodeInstances(TransportService.class)
-            .forEach(ts -> ((MockTransportService) ts).addMessageListener(new TransportMessageListener() {
+            .forEach(ts -> asInstanceOf(MockTransportService.class, ts).addMessageListener(new TransportMessageListener() {
                 @Override
                 public void onResponseSent(long requestId, String action, Exception error) {
                     TransportMessageListener.super.onResponseSent(requestId, action, error);

x-pack/plugin/async-search/src/internalClusterTest/java/org/elasticsearch/xpack/search/AsyncSearchErrorTraceIT.java

@@ -9,6 +9,7 @@
 
 import org.elasticsearch.client.Request;
 import org.elasticsearch.client.Response;
+import org.elasticsearch.common.util.CollectionUtils;
 import org.elasticsearch.common.xcontent.XContentHelper;
 import org.elasticsearch.core.TimeValue;
 import org.elasticsearch.plugins.Plugin;
@@ -20,7 +21,6 @@
 
 import java.io.IOException;
 import java.util.Collection;
-import java.util.List;
 import java.util.Map;
 import java.util.function.BooleanSupplier;
 
@@ -32,8 +32,9 @@ protected boolean addMockHttpTransport() {
     }
 
     @Override
+    @SuppressWarnings("unchecked")
     protected Collection<Class<? extends Plugin>> nodePlugins() {
-        return List.of(AsyncSearch.class, MockTransportService.TestPlugin.class);
+        return CollectionUtils.appendToCopyNoNullElements(super.nodePlugins(), AsyncSearch.class, MockTransportService.TestPlugin.class);
     }
 
     private BooleanSupplier transportMessageHasStackTrace;