List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5); List<Integer> evenNumbers = CollectionUtils.filter(numbers, n -> n % 2 == 0); String text = "Hello, world!"; String reversedText = StringUtils.reverse(text); LocalDate today = LocalDate.now(); LocalDate nextWeek = today.plusWeeks(1); Class<?> clazz = MyClass.class; List<Field> fields = ReflectionUtils.getAllFields(clazz); ExecutorService executor = Executors.newFixedThreadPool(10); CompletableFuture<String> future = ConcurrentUtils.supplyAsync(executor, () -> "Hello, world!");