code: def lstm_bahdanau_attention_multi():
      """Multi-head Bahdanau attention."""
      hparams = lstm_bahdanau_attention()
      hparams.num_heads = 4
      return hparams
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import copy
  from tensor2tensor.layers import area_attention
  from tensor2tensor.layers import common_hparams
  from tensor2tensor.layers import common_layers
  from tensor2tensor.utils import contrib
  from tensor2tensor.utils import registry
  from tensor2tensor.utils import t2t_model
  import tensorflow.compat.v1
  from tensorflow.compat.v1 import estimator
label_desc: Use image node_id 14 for calling a global function with example usage: lstm_bahdanau_attention_multi() and returns: hparams