This method is used only for GroupBy (grouping) views, does nothing for views of other kinds.

When a grouping view is populated, it does not contain empty groups. But later, as a result of maintaining the grouping view, keeping it in synch with changes in its base data, some of the groups can become empty. If it is undesirable to have empty groups, you can call this method to delete them.

Reference

View Class
View Members