String urlString = fragment.toURLString();
        assertNotNull(urlString);
        assertTrue(urlString.contains("text="));
        assertTrue(urlString.contains("start"));

        fragment = new ViewHelper.TextFragment(null, "start", null, null);
        urlString = fragment.toURLString();
        assertNotNull(urlString);
        assertTrue(urlString.contains("text=start"));

            buf.append(url).append("#:~:");
            for (int i = 0; i < textFragmentSize && i < textFragments.length; i++) {
                buf.append(textFragments[i].toURLString()).append('&');
            }
            return buf.toString();
        }
        return url;
    }

    /**
     * Appends search parameters to PDF URLs for highlighting.
     *