class_docstr: Abstract class for bridge tests
class_docstr_tok: ["Abstract","class","for","bridge","tests"]
code: def setUp(self):
      super(BridgeTest, self).setUp()
      self.batch_size = 4
      self.encoder_cell = tf.contrib.rnn.MultiRNNCell(
          [tf.contrib.rnn.GRUCell(4), tf.contrib.rnn.GRUCell(8)]
      )
      self.decoder_cell = tf.contrib.rnn.MultiRNNCell(
          [tf.contrib.rnn.LSTMCell(16), tf.contrib.rnn.GRUCell(8)]
      )
      final_encoder_state = nest.map_structure(
          lambda x: tf.convert_to_tensor(
              value=np.random.randn(self.batch_size, x),
              dtype=tf.float32,
          ),
          self.encoder_cell.state_size,
      )
      self.encoder_outputs = EncoderOutput(
          outputs=tf.convert_to_tensor(
              value=np.random.randn(self.batch_size, 10, 16),
              dtype=tf.float32,
          ),
          attention_values=tf.convert_to_tensor(
              value=np.random.randn(self.batch_size, 10, 16),
              dtype=tf.float32,
          ),
          attention_values_length=np.full([self.batch_size], 10),
          final_state=final_encoder_state,
      )
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  from __future__ import unicode_literals
  from collections import namedtuple
  import numpy
  import tensorflow
  from tensorflow.python.util import nest
  from seq2seq.encoders.encoder import EncoderOutput
  from seq2seq.models.bridges import ZeroBridge, InitialStateBridge
  from seq2seq.models.bridges import PassThroughBridge
label_desc: Use image node_id 1 for calling the BridgeTest obj's underlying member method code with example usage: obj.setUp() without return types