/** The Constant VALIDATOR_FACTORY. */
    static final ValidatorFactory VALIDATOR_FACTORY = Validation.byDefaultProvider()
        .configure()
        .buildValidatorFactory();

    /** The Constant VALIDATOR. */
    static final Validator VALIDATOR = VALIDATOR_FACTORY.getValidator();

    public static class WithMap {

        @Valid
        final private Map<String, @Size(min = 1) List<String>> lists;

        public WithMap(Map<String, List<String>> lists) {
            super();
            this.lists = lists;
        }

        public Map<String, List<String>> getLists() {
            return this.lists;
        }

    }

    /**
     * Test fails as it does not consider the property path when checking if already validated.
     */
    @Test
    public void testSameInstance() {

        List<String> emptyList = new ArrayList<>();

        String[] stringArray = { "A" };

        List<String> populatedList = Arrays.asList(stringArray);

        HashMap<String, List<String>> map = new HashMap<>();
        map.put("POPULATED", populatedList);
        map.put("EMPTY_LIST1", emptyList);
        map.put("EMPTY_LIST2", emptyList);

        WithMap withMap = new WithMap(map);

        Set<ConstraintViolation<WithMap>> constraintViolations = VALIDATOR.validate(withMap);

        // java.lang.AssertionError: expected:<2> but was:<1>
        assertEquals(2, constraintViolations.size());
    }

    /**
     * Test passes since the lists are different instances.
     */
    @Test
    public void testDifferentInstance() {

        String[] stringArray = { "A" };

        List<String> populatedList = Arrays.asList(stringArray);

        HashMap<String, List<String>> map = new HashMap<>();
        map.put("POPULATED", populatedList);
        map.put("EMPTY_LIST1", new ArrayList<>());
        map.put("EMPTY_LIST2", new ArrayList<>());

        WithMap withMap = new WithMap(map);

        Set<ConstraintViolation<WithMap>> constraintViolations = VALIDATOR.validate(withMap);

        // Passes
        assertEquals(2, constraintViolations.size());
    }