docs: def gen_token_range(self, start_id, stop_id):
          """
          returns a list of all token IDs in the given, left-closed,
          right-open interval (i.e. includes start_id, but excludes stop_id)
  
          >>> gen_token_range('T0', 'T1')
          ['T0']
  
          >>> gen_token_range('T1', 'T5')
          ['T1', 'T2', 'T3', 'T4']
          """
          index_range = range(self.tokenid2index(start_id), self.tokenid2index(stop_id))
          return ["T{}".format(index) for index in index_range]