code: def redo_next_change(self):
          
          if len(self._undone) == 0:
              raise IndexError("Can't redo. Already at latest change.")
          h, s = self._undone.pop()
          self.history.append(h)
          self.final_structure = s
docs: Redo the last undone change in the TransformedStructure.
  
          Raises:
              IndexError: If already at the latest change.