The test open/test/jdk/java/io/File/SymLinks.java has some logic to test Windows specific functionality. A refactor extract method will make the code cleaner and highlight the Windows specific tests more clearly

        // on Windows we test with the DOS hidden attribute set
        if (System.getProperty("os.name").startsWith("Windows")) {
            DosFileAttributeView view = Files
                .getFileAttributeView(file.toPath(), DosFileAttributeView.class);
            view.setHidden(true);
            try {
                assertTrue(file.isHidden());
                assertTrue(link2file.isHidden());
                assertTrue(link2link2file.isHidden());
            } finally {
                view.setHidden(false);
            }
            assertFalse(file.isHidden());
            assertFalse(link2file.isHidden());
            assertFalse(link2link2file.isHidden());
        }

refactor extract method -- extract the inline code to DOS specific test

    static void testDOSHiddenAttributes() throws IOException {
        // on Windows we test with the DOS hidden attribute set
        if (System.getProperty("os.name").startsWith("Windows")) {
            DosFileAttributeView view = Files
                .getFileAttributeView(file.toPath(), DosFileAttributeView.class);
            view.setHidden(true);
            try {
                assertTrue(file.isHidden());
                assertTrue(link2file.isHidden());
                assertTrue(link2link2file.isHidden());
            } finally {
                view.setHidden(false);
            }
            assertFalse(file.isHidden());
            assertFalse(link2file.isHidden());
            assertFalse(link2link2file.isHidden());
        }
    }