public Collection<File> classSearchPath() {
        if (classSearchPath == null) {
            lazy();
            Path bootClassPath = getPathForLocation(PLATFORM_CLASS_PATH);
            Path userClassPath = getPathForLocation(CLASS_PATH);
            classSearchPath = new Path();
            classSearchPath.addAll(bootClassPath);
            classSearchPath.addAll(userClassPath);
        }
        return Collections.unmodifiableCollection(classSearchPath);
    }