result.buildFailure == null
        result.clientFailure == null

        and:
        1 * buildController.fromBuildModel(_, _) >> { Boolean b, BuildTreeModelAction modelAction ->
            modelAction.beforeTasks(modelController)
            modelAction.fromBuildModel(modelController)
        }
        1 * projectsLoadedAction.execute(_) >> result1
        1 * buildFinishedAction.execute(_) >> result2

        cache.maybePrepareModel {
            delegate.beforeTasks(action)
        }
    }

    override fun <T : Any?> fromBuildModel(action: BuildTreeModelAction<out T>): T? {
        return cache.loadOrCreateModel {
            val model = delegate.fromBuildModel(action)
            if (model == null) BuildTreeModel.NullModel else BuildTreeModel.Model(model)
        }.result()
    }

        ActionAdapter adapter = new ActionAdapter(action, payloadSerializer);
        try {
            SerializedPayload result = buildController.fromBuildModel(action.isRunTasks(), adapter);
            return Result.of(result);
        } catch (RuntimeException e) {
            RuntimeException clientFailure = e;
            if (adapter.actionFailure != null) {

 */

package org.gradle.internal.buildtree;

import javax.annotation.Nullable;

public interface BuildTreeModelAction<T> {
    void beforeTasks(BuildTreeModelController controller);

    @Nullable
    T fromBuildModel(BuildTreeModelController controller);

/**
 * Responsible for creating a model from the build tree model.
 */
public interface BuildTreeModelCreator {
    <T> void beforeTasks(BuildTreeModelAction<? extends T> action);

    @Nullable
    <T> T fromBuildModel(BuildTreeModelAction<? extends T> action);