def nas_seq2seq_base():
  """Base parameters for Nas Seq2Seq model.

  The default parameters are set to create the Transformer.

  Returns:
    Hyperparameters for Nas Seq2Seq model.
  """
  hparams = transformer.transformer_base()

  hparams.add_hparam("encoder_num_cells", 6)
  hparams.add_hparam("encoder_left_inputs", [0, 1, 2, 3])
  hparams.add_hparam("encoder_left_layers", [
      "standard_attention", "standard_conv_1x1", "standard_conv_1x1", "identity"
  ])
  hparams.add_hparam("encoder_left_output_dims", [512, 2048, 512, 512])
  hparams.add_hparam("encoder_left_activations",
                     ["none", "relu", "none", "none"])
  hparams.add_hparam("encoder_left_norms",
                     ["layer_norm", "layer_norm", "none", "none"])
  hparams.add_hparam("encoder_right_inputs", [0, 1, 1, 1])
  hparams.add_hparam("encoder_right_layers",
                     ["identity", "dead_branch", "identity", "dead_branch"])
  hparams.add_hparam("encoder_right_activations",
                     ["none", "none", "none", "none"])
  hparams.add_hparam("encoder_right_output_dims", [512, 512, 512, 512])
  hparams.add_hparam("encoder_right_norms", ["none", "none", "none", "none"])
  hparams.add_hparam("encoder_combiner_functions", ["add", "add", "add", "add"])
  hparams.add_hparam("encoder_final_combiner_function", "add")

  hparams.add_hparam("decoder_num_cells", 6)
  hparams.add_hparam("decoder_left_inputs", [0, 1, 2, 3, 4])
  hparams.add_hparam("decoder_left_layers", [
      "standard_attention", "attend_to_encoder", "standard_conv_1x1",
      "standard_conv_1x1", "identity"
  ])
  hparams.add_hparam("decoder_left_activations",
                     ["none", "none", "relu", "none", "none"])
  hparams.add_hparam("decoder_left_output_dims", [512, 512, 2048, 512, 512])
  hparams.add_hparam("decoder_left_norms",
                     ["layer_norm", "layer_norm", "layer_norm", "none", "none"])
  hparams.add_hparam("decoder_right_inputs", [0, 1, 2, 2, 4])
  hparams.add_hparam(
      "decoder_right_layers",
      ["identity", "identity", "dead_branch", "identity", "dead_branch"])
  hparams.add_hparam("decoder_right_activations",
                     ["none", "none", "none", "none", "none"])
  hparams.add_hparam("decoder_right_output_dims", [512, 512, 512, 512, 512])
  hparams.add_hparam("decoder_right_norms",
                     ["none", "none", "none", "none", "none"])
  hparams.add_hparam("decoder_combiner_functions",
                     ["add", "add", "add", "add", "add"])
  hparams.add_hparam("decoder_final_combiner_function", "add")

  return hparams
Base parameters for Nas Seq2Seq model.

  The default parameters are set to create the Transformer.

  Returns:
    Hyperparameters for Nas Seq2Seq model.
  
tensor2tensor/models/neural_architecture_search/nas_model.py