*
     * @param c the character to check
     * @return {@code true} if the character is a valid URL character, {@code false} otherwise
     */
    public static boolean isUrlChar(final char c) {
        if (c >= 'a' && c <= 'z' //
                || c >= 'A' && c <= 'Z' //
                || c >= '0' && c <= '9' //
                || c == '.' //
                || c == '-' //
                || c == '*' //

                    || PRIORITY_ELEMENT.equals(qName)) {
                buf = new StringBuilder();
            }
        }

        @Override
        public void characters(final char[] ch, final int offset, final int length) {
            if (buf != null) {
                buf.append(new String(ch, offset, length));
            }
        }

        @Override

        assertEquals(longId.toString(), testRule.getRuleId());

        // Special characters in rule ID
        testRule.setRuleId("rule-id_with.special@chars#123");
        assertEquals("rule-id_with.special@chars#123", testRule.getRuleId());

        // Unicode characters
        testRule.setRuleId("ルール日本語");
        assertEquals("ルール日本語", testRule.getRuleId());

        // Whitespace

        assertEquals("name with spaces", testTransformer.getName());

        // Test with special characters
        testTransformer.setName("name-with_special.chars#123");
        assertEquals("name-with_special.chars#123", testTransformer.getName());

        // Test with Unicode characters
        testTransformer.setName("変換器の名前");
        assertEquals("変換器の名前", testTransformer.getName());

    }

    private static boolean isLastSpaceChar(final StringBuilder buf) {
        if (buf.length() == 0) {
            return false;
        }
        return buf.charAt(buf.length() - 1) == ' ';
    }

    private static boolean removeLastDuplication(final StringBuilder buf, final int size, final boolean isSpace,
            final Set<String> termCache) {

        if (!filePath.startsWith("file:")) {
            filePath = "file://" + filePath;
        }

        final StringBuilder buf = new StringBuilder(filePath.length() + 100);
        try {
            for (final char c : filePath.toCharArray()) {
                if (c == ' ') {
                    buf.append("%20");
                } else {
                    final String str = String.valueOf(c);

        }

        final long start = System.currentTimeMillis();
        final StringBuilder buf = new StringBuilder(searchWord.length());
        char prev = 0;
        for (final char c : searchWord.toCharArray()) {
            if (!Character.isWhitespace(c)) {
                buf.append(c);
            } else if (!Character.isWhitespace(prev)) {
                buf.append(' ');

    }

    /**
     * Test constructor with special characters in message
     */
    public void test_constructor_withSpecialCharactersInMessage() {
        String message = "Error: \n\t\r\0\b\f with special chars #@!$%^&*()[]{}";
        CrawlerSystemException exception = new CrawlerSystemException(message);

        assertNotNull(exception);
        assertEquals(message, exception.getMessage());
    }

    /**

        if (matchWordFirst && !hiraganaQuery && singleWordQuery && text.contains(query)) {
            if (query.length() == 1) {
                return UnicodeBlock.of(query.charAt(0)) != UnicodeBlock.HIRAGANA;
            }
            return true;
        }
        return false;
    }

    /**
     * Checks if the query is a hiragana query.

        if (StringUtil.isBlank(url) || StringUtil.isBlank(enc)) {
            return url;
        }

        final StringBuilder buf = new StringBuilder(url.length() + 100);
        for (final char c : url.toCharArray()) {
            if (CharUtil.isUrlChar(c)) {
                buf.append(c);
            } else {
                try {
                    buf.append(URLEncoder.encode(String.valueOf(c), enc));