String newSpecialInput = "new!@#$%";
        item.setNewInput(newSpecialInput);
        assertEquals(newSpecialInput, item.toLineString());
    }

    @Test
    public void test_whitespaceHandling() {
        // Test with various whitespace
        StopwordsItem item1 = new StopwordsItem(1, " ");
        assertEquals(" ", item1.getInput());
        assertEquals(" ", item1.toLineString());