*
     * @param hash the encoded hash string to decode
     * @return the decoded hash string, or the original hash if decoding fails
     */
    public String decodeSimilarDocHash(final String hash) {
        if (hash != null && hash.startsWith(SIMILAR_DOC_HASH_PREFIX) && hash.length() > SIMILAR_DOC_HASH_PREFIX.length()) {

                    context.addQuery(boolQuery -> {
                        boolQuery.filter(QueryBuilders.termQuery(fessConfig.getIndexFieldContentMinhashBits(),
                                documentHelper.decodeSimilarDocHash(similarDocHash)));
                    });
                }

                if (geoInfo != null && geoInfo.toQueryBuilder() != null) {