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/GetBlobChecksumAction.java
import org.elasticsearch.core.IOUtils;
import org.elasticsearch.repositories.RepositoriesService;
import org.elasticsearch.repositories.Repository;
import org.elasticsearch.repositories.RepositoryVerificationException;
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.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.nio.file.NoSuchFileException;
import java.util.Map;
import java.util.concurrent.atomic.AtomicLong;
import java.util.zip.CRC32;
/**
 * Action which instructs a node to read a range of a blob from a {@link org.elasticsearch.repositories.blobstore.BlobStoreRepository}
 * (possibly the entire blob) and compute its checksum. It is acceptable if the blob is not found but we do not accept the blob being
 * otherwise unreadable.
 */
public class GetBlobChecksumAction extends ActionType<GetBlobChecksumAction.Response> {
    private static final Logger logger = LogManager.getLogger(GetBlobChecksumAction.class);
    public static final GetBlobChecksumAction INSTANCE = new GetBlobChecksumAction();
    public static final String NAME = "cluster:admin/repository/analyze/blob/read";
    private GetBlobChecksumAction() {
        super(NAME, Response::new);
    }
    public static class TransportAction extends HandledTransportAction<Request, Response> {