fail("Should throw NullPointerException for null input");
        } catch (NullPointerException e) {
            // Expected behavior
        }
    }

    public void test_parse_null_input() {
        // Test null input handling
        try {
            KuromojiCSVUtil.parse(null);
            fail("Should throw NullPointerException for null input");
        } catch (NullPointerException e) {