* toRooArray($request) : array
* - called if singleArray is unavailable on single fetch.
* - always tried for mutiple results.
- * toArray() - the default method if none of the others are found.
+ * toArray() - the default method if none of the others are found.
+ * toSimpleExcelColumn($col) - see toCSV - this enables special columns to be created for exported data.
*
* autoJoin($request)
* - standard DataObject feature - causes all results to show all