*  <br>
     * comment: HTTP headers for the response.
     * @return The value of found property. (NotNull: if not found, exception but basically no way)
     */
    String getResponseHeaders();

    /**
     * Get the value for the key 'index.document.search.index'. <br>
     * The value is, e.g. fess.search <br>
     * comment: Index name for search documents.