Actions `cluster:admin/repository/analyze/blob` and `cluster:admin/repository/analyze/register` and so on are only invoked via the transport service, they do not need to register as client actions so we can drop the `ActionType` instance. Instead the root `RepositoryAnalyzeAction` should create and register all these transport actions itself. But even the root `RepositoryAnalyzeAction` should not be an `ActionType` derivative, we should just declare an `ActionType` instance directly. Moreover we can use `ActionType#localOnly` since the client action does not run on remote clusters.
x-pack/plugin/snapshot-repo-test-kit/src/main/java/org/elasticsearch/repositories/blobstore/testkit/ContendedRegisterAnalyzeAction.java
import org.elasticsearch.common.bytes.BytesArray;
import org.elasticsearch.common.bytes.BytesReference;
import org.elasticsearch.common.inject.Inject;
import org.elasticsearch.common.io.stream.StreamInput;
import org.elasticsearch.common.io.stream.StreamOutput;
import org.elasticsearch.common.util.ByteUtils;
import org.elasticsearch.repositories.RepositoriesService;
import org.elasticsearch.repositories.Repository;
import org.elasticsearch.repositories.blobstore.BlobStoreRepository;
import org.elasticsearch.tasks.CancellableTask;
import org.elasticsearch.tasks.Task;
import org.elasticsearch.tasks.TaskId;
import org.elasticsearch.threadpool.ThreadPool;
import org.elasticsearch.transport.TransportService;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.Map;
import java.util.concurrent.ExecutorService;
/**
 * An action which atomically increments a register using {@link BlobContainer#compareAndExchangeRegister}. There will be multiple parties
 * accessing the register concurrently in order to test behaviour under contention.
 */
public class ContendedRegisterAnalyzeAction extends ActionType<ActionResponse.Empty> {
    private static final Logger logger = LogManager.getLogger(ContendedRegisterAnalyzeAction.class);
    public static final ContendedRegisterAnalyzeAction INSTANCE = new ContendedRegisterAnalyzeAction();
    public static final String NAME = "cluster:admin/repository/analyze/register";
    private ContendedRegisterAnalyzeAction() {
        super(NAME, in -> ActionResponse.Empty.INSTANCE);
    }
    public static class TransportAction extends HandledTransportAction<Request, ActionResponse.Empty> {