运行pointer模型，报以下错误

[zcqiand]

File "D:\App\novel\FunText\src\models\pointernet\PointerNetGenerator.py", line 108, in _build_decoder_cell
initial_state = cell.zero_state(self._batch_size, tf.float32).clone(cell_state=cell_state)
File "D:\App\novel\FunText\src\models\pointernet\PointerNetHelper.py", line 202, in zero_state
for _ in self._attention_mechanisms))
TypeError: new() missing 1 required positional argument: 'attention_state'