code: def reset_undo(self):
      self.was_saved = -1
      self.pointer = 0
      self.undolist = []
      self.undoblock = 0  # or a CommandSequence instance
      self.set_saved(1)
  
imports: import string
  from idlelib.delegator import Delegator
label_desc: Use image node_id 4 for calling the UndoDelegator obj's underlying member method code with example usage: obj.reset_undo() without return types