Perform a single undo. Calling this function when there are no undo operations available is an error. Use gtksource.undo_manager.UndoManager.canUndo to find out if there are undo operations available.
Perform a single undo. Calling this function when there are no undo operations available is an error. Use gtksource.undo_manager.UndoManager.canUndo to find out if there are undo operations available.