The type of the selected group. The value esigtNone means that an individual element is selected (or all items), instead a group of items.Values: STRUCTURE_ITEM_GROUP_TYPE_NONE (0), STRUCTURE_ITEM_GROUP_TYPE_BUILT_IN (1), STRUCTURE_ITEM_GROUP_TYPE_USER_DEFINED (2), STRUCTURE_ITEM_GROUP_TYPE_VIEWS_BY_SELECTED_USER (3), STRUCTURE_ITEM_GROUP_TYPE_HANDLERS_OF_SELECTED_EVENT_HANDLER_TYPE (4).