private ProjectState addProject(BuildState owner, DefaultBuildProjectRegistry projectRegistry, DefaultProjectDescriptor descriptor) {
        Path projectPath = descriptor.path();
        Path identityPath = owner.calculateIdentityPathForProject(projectPath);
        String name = descriptor.getName();
        ProjectComponentIdentifier projectIdentifier = new DefaultProjectComponentIdentifier(owner.getBuildIdentifier(), identityPath, projectPath, name);

    @Override
    public <T> T run(Function<? super BuildTreeLifecycleController, T> buildAction) {
        return buildAction.apply(buildTreeLifecycleController);
    }

    @Override
    public Path calculateIdentityPathForProject(Path projectPath) {
        return getBuildController().getGradle().getIdentityPath().append(projectPath);
    }

    @Override
    public File getBuildRootDir() {

        }
    }

    @Override
    public File getBuildRootDir() {
        return buildDefinition.getBuildRootDir();
    }

    @Override
    public Path calculateIdentityPathForProject(Path projectPath) {
        return getIdentityPath().append(projectPath);
    }

    @Override
    public Action<? super DependencySubstitutions> getRegisteredDependencySubstitutions() {

    }

    @Override
    public StartParameterInternal getStartParameter() {
        return getBuildController().getGradle().getStartParameter();
    }

    @Override
    public Path calculateIdentityPathForProject(Path path) {
        return path;
    }

    @Override
    protected void ensureChildBuildConfigured() {
        // nothing to do for the root build
    }

     */
    boolean isImportableBuild();

    /**
     * Calculates the identity path for a project in this build.
     */
    Path calculateIdentityPathForProject(Path projectPath) throws IllegalStateException;

    /**
     * Loads the projects for this build so that {@link #getProjects()} can be used, if not already done.

    public Path getIdentityPath() {
        return identityPath;
    }

    @Override
    public boolean isImplicitBuild() {
        return false;
    }

    @Override
    public Path calculateIdentityPathForProject(Path projectPath) {
        return getBuildController().getGradle().getIdentityPath().append(projectPath);
    }

    @Override
    public File getBuildRootDir() {

            return Path.ROOT;
        }

        @Override
        public boolean isImplicitBuild() {
            return false;
        }

        @Override
        public Path calculateIdentityPathForProject(Path projectPath) {
            return projectPath;
        }

        @Override
        public StartParameterInternal getStartParameter() {
            throw new UnsupportedOperationException();

        def build = Stub(BuildState)
        build.loadedSettings >> settings
        build.buildIdentifier >> DefaultBuildIdentifier.ROOT
        build.identityPath >> Path.ROOT
        build.calculateIdentityPathForProject(_) >> { Path path -> path }
        def services = new DefaultServiceRegistry()
        services.add(projectFactory)
        services.add(TestUtil.stateTransitionControllerFactory())