code: def reset(self, state_size_changed=False):
          
          if state_size_changed:
              self.state = deque(repeat('', self.state_size),
                                 maxlen=self.state_size)
          else:
              self.state.extend(repeat('', self.state_size))
          self.end = True
docs: Reset parser state.
  
          Parameters
          ----------
          state_size_changed : `bool`, optional
              `True` if maximum state size changed (default: `False`).