TestFileChangeListener listener = new TestFileChangeListener();
File dir = getTempDir();
FileSystemWatcher watcher = new FileSystemWatcher(listener, -1, "test");
pause(1000);
File f1 = create(dir, "Book$1.class");
watcher.register(f1);
pause(1100);
File f2 = create(dir, "Book.class");
watcher.register(f2);
pause(1100);
File f3 = create(dir, "Book$_2.class");