* @return The value of found property. (NotNull: if not found, exception but basically no way)
     * @throws NumberFormatException When the property is not integer.
     */
    Integer getSearchlogAggShardSizeAsInteger();

    /**
     * Get the value for the key 'searchlog.request.headers'. <br>
     * The value is, e.g.  <br>
     * comment: Request headers to include in search log.