/**
     * Creates an implicit included build. An implicit build is-a nested build that is managed by Gradle and whose outputs are used by dependency resolution.
     */
    IncludedBuildState addImplicitIncludedBuild(BuildDefinition buildDefinition);

    /**
     * Locates the buildSrc build for the given build, if present. Returns null if the given build does not have an associated buildSrc build.
     */
    @Nullable

                BuildDefinition buildDefinition = toBuildDefinition((AbstractVersionControlSpec) spec, buildRootDir);
                IncludedBuildState includedBuild = buildRegistry.addImplicitIncludedBuild(buildDefinition);

                Collection<Pair<ModuleVersionIdentifier, ProjectComponentIdentifier>> moduleToProject = includedBuild.getAvailableModules();

        return registerBuild(buildDefinition, false, buildPath);
    }

    @Override
    public synchronized IncludedBuildState addImplicitIncludedBuild(BuildDefinition buildDefinition) {
        // TODO: synchronization with other methods
        IncludedBuildState includedBuild = includedBuildsByRootDir.get(buildDefinition.getBuildRootDir());

        registry.attachRootBuild(rootBuild())
        includedBuildFactory.createBuild(buildIdentifier(":b1"), buildDefinition, true, _ as BuildState) >> includedBuild

        when:
        def result = registry.addImplicitIncludedBuild(buildDefinition)
        then:
        1 * buildAddedListener.buildAdded(includedBuild)
        0 * _

        result.is(includedBuild)

        registry.includedBuilds as List == [includedBuild]