message: Fix describe, argument `sequence_lengths` in seq2seq.Decoder.finalize
diff: @@ -119,7 +119,7 @@ class Decoder(object):
  steps.
  final_state: RNNCell final state (possibly nested tuple of) tensor[s] for
  last time step.
  - sequence_lengths: Scalar `int32` tensor. Maximum sequence length.
  + sequence_lengths: `int32` tensor containing lengths of each sequences.
  Returns:
  `(final_outputs, final_state)`: `final_outputs` is an object containing
  