Version to use for seq2seq.

def attention_lm_translation():
  """Version to use for seq2seq."""
  hparams = attention_lm_base()
  hparams.layer_preprocess_sequence = "n"
  hparams.layer_postprocess_sequence = "da"
  hparams.learning_rate = 0.4
  hparams.prepend_mode = "prepend_inputs_masked_attention"
  hparams.max_length = 512
  hparams.label_smoothing = 0.1
  hparams.shared_embedding_and_softmax_weights = True
  return hparams