true, if data grouping is applied; otherwise, false.
The grid allows you to group data by a single column (see the How to: Group Data example).
Groups of data rows (rows that have identical values in the specified column) are separated with group rows that a user can tap to expand or collapse groups. You can also display summary information about groups (for example, sum of values, the number of records, the minimum or maximum value, etc.) on group rows.