assertNotSame(item1.hashCode(), item3.hashCode());

        // Consistent hashCode
        assertEquals(item1.hashCode(), item1.hashCode());
    }

    public void test_hashCode_withNullInput() {
        // Test hashCode with null input should throw NullPointerException
        ProtwordsItem item = new ProtwordsItem(1, null);
        try {
            item.hashCode();