}
        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;
    }