*/
    public static Optional<SourceSet> getJavaMainSourceSet(Project project) {
        return isJavaExtensionAvailable(project)
            ? Optional.empty()
            : Optional.ofNullable(getJavaSourceSets(project).findByName(SourceSet.MAIN_SOURCE_SET_NAME));
    }

    private static boolean isJavaExtensionAvailable(Project project) {
        return project.getExtensions().getByType(JavaPluginExtension.class) == null;
    }