private static final String DUPLICATE_HOST_HELPER = "duplicateHostHelper";

    private static final String PATH_MAPPING_HELPER = "pathMappingHelper";

    private static final String POPULAR_WORD_HELPER = "popularWordHelper";

    private static final String CRAWLING_INFO_HELPER = "crawlingInfoHelper";

    private static final String CRAWLING_CONFIG_HELPER = "crawlingConfigHelper";