// Emoji with quotes
        input = "\"🚀\" rocket";
        result = KuromojiCSVUtil.quoteEscape(input);
        assertEquals("\"\"🚀\"\" rocket", result);
    }

    @Test
    public void test_quoteEscape_null_input() {
        // Test null input handling
        try {
            KuromojiCSVUtil.quoteEscape(null);
            fail("Should throw NullPointerException for null input");