}
        convertMap.put(target, replacement);
    }

    /**
     * Sets the conversion map.
     * @param convertMap The conversion map to set.
     */
    public void setConvertMap(final Map<String, String> convertMap) {
        if (convertMap == null) {
            throw new CrawlerSystemException("convertMap is null.");
        }
        this.convertMap = convertMap;
    }

            String[] alphabets;
            if (i + 1 < text.length() && convertMap.get(text.substring(i, i + 2)) != null) {
                alphabets = convertMap.get(text.substring(i, i + 2));
                i += 2;
            } else {
                if (convertMap.get(text.substring(i, i + 1)) != null) {
                    alphabets = convertMap.get(text.substring(i, i + 1));
                } else {