public static <T> Predicate<T> distinctByKey(Function<? super T, Object> keyExtractor) {
        Map<Object, Boolean> seen = new ConcurrentHashMap<>();
        return object -> seen.putIfAbsent(keyExtractor.apply(object), Boolean.TRUE) == null;
    }
@Test
    void shouldReturnTrueForDistinctKeys() {
        Function<Object, Object> keyExtractor = Object::getClass;
        Predicate<Object> distinctByKey = LambdaUtils.distinctByKey(keyExtractor);

        boolean result = distinctByKey.test(new Object());
        assertTrue(result);
    }