Add writeable entry to ML tests

Author: prwhelan

x-pack/plugin/ml/qa/native-multi-node-tests/src/javaRestTest/java/org/elasticsearch/xpack/ml/integration/MlNativeIntegTestCase.java

@@ -20,6 +20,7 @@
 import org.elasticsearch.action.support.master.AcknowledgedResponse;
 import org.elasticsearch.client.internal.Client;
 import org.elasticsearch.client.internal.node.NodeClient;
+import org.elasticsearch.cluster.AbstractNamedDiffable;
 import org.elasticsearch.cluster.ClusterModule;
 import org.elasticsearch.cluster.ClusterState;
 import org.elasticsearch.cluster.NamedDiff;
@@ -59,6 +60,7 @@
 import org.elasticsearch.test.XContentTestUtils;
 import org.elasticsearch.transport.netty4.Netty4Plugin;
 import org.elasticsearch.xcontent.NamedXContentRegistry;
+import org.elasticsearch.xcontent.ParseField;
 import org.elasticsearch.xpack.autoscaling.Autoscaling;
 import org.elasticsearch.xpack.autoscaling.AutoscalingMetadata;
 import org.elasticsearch.xpack.autoscaling.capacity.AutoscalingDeciderResult;
@@ -99,6 +101,7 @@
 import org.elasticsearch.xpack.esql.core.plugin.EsqlCorePlugin;
 import org.elasticsearch.xpack.esql.plugin.EsqlPlugin;
 import org.elasticsearch.xpack.ilm.IndexLifecycle;
+import org.elasticsearch.xpack.inference.registry.ClearInferenceEndpointCacheAction;
 import org.elasticsearch.xpack.inference.registry.ModelRegistryMetadata;
 import org.elasticsearch.xpack.ml.LocalStateMachineLearning;
 import org.elasticsearch.xpack.ml.autoscaling.MlScalingReason;
@@ -436,6 +439,24 @@ protected void assertClusterRoundTrip() throws IOException {
                 new NamedWriteableRegistry.Entry(Metadata.ProjectCustom.class, ModelRegistryMetadata.TYPE, ModelRegistryMetadata::new)
             );
             entries.add(new NamedWriteableRegistry.Entry(NamedDiff.class, ModelRegistryMetadata.TYPE, ModelRegistryMetadata::readDiffFrom));
+            entries.add(
+                new NamedWriteableRegistry.Entry(
+                    Metadata.ProjectCustom.class,
+                    ClearInferenceEndpointCacheAction.InvalidateCacheMetadata.NAME,
+                    ClearInferenceEndpointCacheAction.InvalidateCacheMetadata::new
+                )
+            );
+            entries.add(
+                new NamedWriteableRegistry.Entry(
+                    NamedDiff.class,
+                    ClearInferenceEndpointCacheAction.InvalidateCacheMetadata.NAME,
+                    in -> AbstractNamedDiffable.readDiffFrom(
+                        Metadata.ProjectCustom.class,
+                        ClearInferenceEndpointCacheAction.InvalidateCacheMetadata.NAME,
+                        in
+                    )
+                )
+            );
 
             // Retrieve the cluster state from a random node, and serialize and deserialize it.
             final ClusterStateResponse clusterStateResponse = client().admin()