redo method
      
void
redo()
      
     
    
After an #undo, re-perform the changes in #transactionToRedo. #canRedo must be true for this method to have any effect.
This is called by CommandHandler#redo.
This will raise a "StartingRedo" ChangedEvent of type ChangedEvent.Transaction, perform the Transaction#redo on the #transactionToRedo, and then raise a "FinishedRedo" ChangedEvent of type ChangedEvent.Transaction. The two ChangedEvents are to let model listeners know that a redo is about to take place and that it just finished. #isUndoingRedoing will temporarily be set to true during this operation.
Implementation
void redo() {
  _i4.callMethod(
    this,
    'redo',
    [],
  );
}