assertArgumentNotNull("referenceClass", referenceClass);

        final URL url = ResourceUtil.getResource(toClassFile(referenceClass.getName()));
        final String[] path = referenceClass.getName().split("\\.");
        String baseUrl = url.toExternalForm();
        for (final String element : path) {
            final int pos = baseUrl.lastIndexOf('/');
            baseUrl = baseUrl.substring(0, pos);
        }

     */
    protected static File getPackageDir(final File rootDir, final String rootPackage) {
        File packageDir = rootDir;
        if (rootPackage != null) {
            for (final String name : rootPackage.split("\\.")) {
                packageDir = new File(packageDir, name);
            }
        }
        return packageDir;
    }

        assertArgumentNotNull("rootDir", rootDir);

        File baseDir = rootDir;
        if (baseDirectory != null) {
            for (final String name : baseDirectory.split("/")) {
                baseDir = new File(baseDir, name);
            }
        }
        return baseDir;
    }

        return new StreamOf<>(() -> values != null ? Arrays.stream(values) : Collections.<T> emptyList().stream());
    }

    public static StreamOf<String> split(final String value, final String regex) {
        return stream(value == null ? null : value.split(regex));
    }

    public static <K, V> StreamOf<Map.Entry<K, V>> stream(final Map<K, V> map) {

        final String[] array = StringUtil.split("aaa\nbbb", "\n");
        assertEquals("1", 2, array.length);
        assertEquals("2", "aaa", array[0]);
        assertEquals("3", "bbb", array[1]);
    }

    /**
     *
     */
    @Test
    public void testSplit2() {
        final String[] array = StringUtil.split("aaa, bbb", ", ");
        assertEquals("1", 2, array.length);

    }

    /**
     * 文字列を分割します。
     *
     * @param str
     *            文字列
     * @param delim
     *            分割するためのデリミタ
     * @return 分割された文字列の配列
     */
    public static String[] split(final String str, final String delim) {
        if (isEmpty(str)) {
            return EMPTY_STRINGS;
        }
        final List<String> list = newArrayList();

        assertArgumentNotEmpty("path", path);

        File dir = null;
        final URL url = getResource(path);
        if ("file".equals(url.getProtocol())) {
            final int num = path.split("/").length;
            dir = new File(getFileName(url));
            for (int i = 0; i < num; ++i) {
                dir = dir.getParentFile();
            }
        } else {