* @param maxWidth the maximum width of the digest
     * @return the abbreviated and normalized digest, or empty string if content is null
     */
    public String getDigest(final ResponseData responseData, final String content, final Map<String, Object> dataMap, final int maxWidth) {
        if (content == null) {
            return StringUtil.EMPTY; // empty
        }

            putResultDataBody(dataMap, fessConfig.getIndexFieldDigest(), digest);
        } else {
            putResultDataBody(dataMap, fessConfig.getIndexFieldDigest(),
                    documentHelper.getDigest(responseData, body, dataMap, fessConfig.getCrawlerDocumentHtmlMaxDigestLengthAsInteger()));
        }
        // segment
        putResultDataBody(dataMap, fessConfig.getIndexFieldSegment(), sessionId);
        // host