code: def att_sum_bahdanau(v_att, keys, query):
      """Calculates a batch- and timweise dot product with a variable"""
      return tf.reduce_sum(
          v_att * tf.tanh(keys + tf.expand_dims(query, 1)), [2]
      )
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  from __future__ import unicode_literals
  import abc
  import six
  import tensorflow
  from tensorflow.python.framework import function
  from seq2seq.graph_module import GraphModule
  from seq2seq.configurable import Configurable
label_desc: Use image node_id 1 for calling a global function with example usage: att_sum_bahdanau(v_att, keys, query) and returns: tf