"filter" : ["lowercase", "stopword_en_filter", "pos_filter", "content_length_filter", "limit_token_count_filter"]
      },
      "contents_reading_analyzer" : {
        "type" : "custom",
        "tokenizer" : "kuromoji_neologd_normal",
        "char_filter" : ["mapping_char"],
        "filter" : ["lowercase", "stopword_en_filter", "pos_filter", "content_length_filter", "limit_token_count_filter", "reading_form"]
      },

     *
     * @param inputStream An input stream.
     * @param params A map of parameters.
     * @param postFilter A post filter.
     * @return An extracted data.
     */
    protected ExtractData getText(final InputStream inputStream, final Map<String, String> params,
            final BiConsumer<ExtractData, InputStream> postFilter) {
        if (inputStream == null) {
            throw new CrawlerSystemException("The inputstream is null.");