public void test_isUrlChar_commonSpecialChars() {
        // Test common special characters
        assertTrue(CharUtil.isUrlChar('.'));
        assertTrue(CharUtil.isUrlChar('-'));
        assertTrue(CharUtil.isUrlChar('*'));
        assertTrue(CharUtil.isUrlChar('_'));
    }

    public void test_isUrlChar_urlSpecialChars() {
        // Test URL-specific special characters
        assertTrue(CharUtil.isUrlChar(':'));

    public void test_escapeXml_allSpecialChars() {
        // Test all special characters
        String input = "Test & < > \"quote\" 'apos'";
        String expected = "Test &amp; &lt; &gt; &quot;quote&quot; &apos;apos&apos;";
        assertEquals(expected, XmlUtil.escapeXml(input));
    }

    public void test_escapeXml_noSpecialChars() {
        // Test string without special characters
        String input = "Simple text without special characters";

 * Utility class for XML-related operations.
 *
 * This class provides methods to escape special characters in XML strings,
 * strip invalid XML characters, and parse XML content into a map of data.
 *
 * <p>
 * The class is final and cannot be instantiated.
 * </p>
 *
 * <h2>Methods:</h2>
 * <ul>
 *   <li>{@link #escapeXml(String)}: Escapes special characters in an XML string.</li>

     * The value is, e.g. 0 <br>
     * comment: <br>
     * one day: 86400000, three days: 259200000, five days: 432000000, one week: 604800000, one year: 31556926000<br>
     * special script :: absolute mode: $(2014/07/10), relative mode: addDay(3).addMonth(4)<br>
     * The milliseconds for (relative or absolute) adjust time (set only when test) @LongType *dynamic in development

    /**
     * Checks if the given character is a valid URL character.
     *
     * Valid URL characters include:
     * - Lowercase letters (a-z)
     * - Uppercase letters (A-Z)
     * - Digits (0-9)
     * - Special characters: . - * _ : / + % = & ? # [ ] @ ~ ! $ ' ( ) , ;
     *
     * @param c the character to check
     * @return {@code true} if the character is a valid URL character, {@code false} otherwise
     */

 *
 * <p>
 * This class provides methods to:
 * </p>
 * <ul>
 *   <li>Detect the MIME type based on the input stream and filename.</li>
 *   <li>Normalize the filename to handle special characters.</li>
 *   <li>Configure whether to use the filename for MIME type detection.</li>
 *   <li>Configure whether to use the filename for MIME type detection when the stream is octet-stream.</li>
 * </ul>
 *
 * <p>

    }

    @Test
    public void testParseQueryWithSpecialCharacters() {
        // Test query with special characters
        String query = "test+query-search";
        String field = "content";
        String[] keywords = SuggestUtil.parseQuery(query, field);
        assertNotNull(keywords);
        // Parser should handle special characters
    }

    @Test
    public void testGetTermQueryListWithNull() {

        } catch (final CrawlerSystemException e) {
            assertEquals("The inputstream is null.", e.getMessage());
        }
    }

    /**
     * Test extraction with filename containing special characters.
     */
    public void test_getText_withSpecialCharactersInFilename() {
        final InputStream in = new ByteArrayInputStream(new byte[0]);
        final Map<String, String> params = new HashMap<>();

    @Test
    public void testEncodingSpecialCharacters() {
        CurlRequest request = new CurlRequest(Method.GET, "https://example.com");

        // Test encoding of special characters
        request.param("query", "hello world & more");
        request.param("special", "ñ€±");

        // Should not throw exception
        assertNotNull(request);
    }

    @Test
    public void testUnsupportedEncodingThrowsException() {

            assertTrue("Error message should contain 'text content'", message.contains("text content"));
        }
    }

    /**
     * Test extraction with special characters and control characters.
     */
    public void test_getText_withSpecialCharacters_handlesCorrectly() {
        final String specialContent = "Tab\there\nNewline\rCarriage return\0Null byte";