### Question:
FileUtils { public static String extension(Path path) { String name = path.toFile().getName(); int dotIndex = name.lastIndexOf(DOT); if (dotIndex > 0) { return name.substring(dotIndex); } return EMPTY; }  static Path find(File dir, String pattern); static Path tryFind(File dir, String pattern); static String slashify(String path); static String unslashify(String path); static boolean copy(File src, File dest); static void chmod757(String path); static boolean chmod(String path, boolean recursive,
                                boolean readable, boolean writable, boolean executable); static String baseName(String path); static String extension(Path path); static void createIfAbsent(FileSystem fs, String path, Handler<AsyncResult<Void>> handler); static void deleteIfPresent(FileSystem fs, String path, Handler<AsyncResult<Void>> handler); static void readFiles(FileSystem fs, String path, String filter,
                                 Handler<AsyncResult<Map<String, String>>> handler); static List<String> readResource(String resourcePath); static final String NEW_LINE; static final String SLASH; static final String DOT_SLASH; static final String COLON; }### Answer:
@Test public void extensionTest() { Assert.assertEquals("Extension should be 'js'.", ".js", FileUtils.extension(new File("/buildpal/core/util/script.js").toPath())); }