group (section) {
        logger.warnOnce('consider using dataTable.section instead of dataTable.group for clarity');
        if (!arguments.length) {
            return this.section();
        }
        return this.section(section);
    }
Backward-compatible synonym for {@link DataTable#section section}.

@param {Function} section Function taking a row of data and returning the nest key.
@returns {Function|DataTable}