function Leadtools.Annotations.Automation.AnnAutomation.undo()
If the CanUndo property returns true, this method will undo the last operation performed in this AnnAutomation.
Use the UndoCapacity property to get or set the number of user actions that can be reversed using the Undo method, or reapplied using the Redo method. The default for the UndoCapacity property is 10 actions.
For information on undoing or redoing automation operations, refer to Undoing Annotation Automation Operations.
For an example, refer to BeginUndo.