this.parent = parent;
            return this;
        }

        public BuildOperationDescriptor build() {
            return build(null, null);
        }

        @Nullable
        BuildOperationRef getParentState() {
            return parent;
        }

        public BuildOperationDescriptor build(@Nullable OperationIdentifier id, @Nullable OperationIdentifier defaultParentId) {

        then:
        1 * listener.progress(_, _) >> { BuildOperationDescriptor descriptor, String status ->
            assert status == "progress 1"
        }
        1 * listener.progress(_, _) >> { BuildOperationDescriptor descriptor, String status ->
            assert status == "progress 2"
        }
        1 * listener.progress(_, _, _, _, _) >> { BuildOperationDescriptor descriptor, long progress, long total, String units, String status ->

        }
    }

    private static abstract class Operation {
        public abstract void generateStartEvent(BuildOperationDescriptor buildOperation, OperationStartEvent startEvent);

        public abstract void generateFinishEvent(BuildOperationDescriptor buildOperation, OperationFinishEvent finishEvent);

        public abstract void progress(OperationProgressEvent progressEvent);
    }

internal
fun <T : Any> BuildOperationRunner.withLoadOperation(block: () -> Pair<LoadResult, T>) =
    call(object : CallableBuildOperation<T> {
        override fun description(): BuildOperationDescriptor.Builder = BuildOperationDescriptor
            .displayName("Load configuration cache state")
            .progressDisplayName("Loading configuration cache state")
            .details(LoadDetails)

        override fun call(context: BuildOperationContext): T =

                                    queue.add(new RunnableBuildOperation() {
                                        @Override
                                        public BuildOperationDescriptor.Builder description() {
                                            return BuildOperationDescriptor.displayName("test operation")
                                        }

                                        @Override

    public void run(BuildOperationContext context) {
        state.getMetadataOrNull();
    }

    @Override
    public BuildOperationDescriptor.Builder description() {
        return BuildOperationDescriptor.displayName("Resolve " + state);
    }

            null,
            buildOperationDescriptor.getId(),
            category,
            progressListener,
            clock,
            true,
            buildOperationDescriptor.getId(),
            buildOperationDescriptor.getParentId(),
            buildOperationCategory
        );
        logger.totalProgress = buildOperationDescriptor.getTotalProgress();

import org.gradle.internal.build.event.types.DefaultSuccessResult;
import org.gradle.internal.operations.BuildOperationCategory;
import org.gradle.internal.operations.BuildOperationDescriptor;
import org.gradle.internal.operations.BuildOperationIdFactory;
import org.gradle.internal.operations.BuildOperationListener;
import org.gradle.internal.operations.OperationFinishEvent;

        void progress(BuildOperationDescriptor descriptor, String status);

        void progress(BuildOperationDescriptor descriptor, long progress, long total, String units, String status);

        void stop(BuildOperationDescriptor descriptor, BuildOperationState operationState, @Nullable BuildOperationState parent, ReadableBuildOperationContext context);

        void close(BuildOperationDescriptor descriptor, BuildOperationState operationState);

        buildOperationRunner.call(new CallableBuildOperation<Void>() {
            @Override
            public BuildOperationDescriptor.Builder description() {
                //noinspection Convert2Lambda
                return BuildOperationDescriptor
                    .displayName("Load projects")
                    .progressDisplayName("Loading projects")