Base interface intended to be implemented byFToolCommandChangesubclasses that represent changes to a FGeometrySelection. The point of the interface is to allowUGeometrySelectionManagerto execute theApplyChange()andRevertChange()with the FGeometrySelectionEditor it provides. So the call pattern is that theFToolCommandChange::Apply(), with theUGeometrySelectionManageras theUObjecttarget, will callUGeometrySelectionManager::ApplyChange(), which then in turn will callIGeometrySelectionChange::ApplyChange()