code: def testWrapperBuild(self):
      wrapper = rnn_wrapper.RNNWrapper(
          tf.keras.layers.LSTM(
              3, return_state=True, return_sequences=True
          )
      )
      # Make sure wrapper.build() works when no time dimension is passed in.
      wrapper.build((1, 4))
      self.evaluate(tf.compat.v1.global_variables_initializer())
      variables = self.evaluate(wrapper.trainable_variables)
      self.assertLen(variables, 3)
      self.assertLen(wrapper.variables, 3)
      self.assertTrue(wrapper.trainable)
      wrapper.trainable = False
      self.assertFalse(wrapper.trainable)
      self.assertEmpty(wrapper.trainable_variables)
      self.assertLen(wrapper.variables, 3)
  
file_path: agents/tf_agents/keras_layers/rnn_wrapper_test.py
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import numpy
  import tensorflow.compat.v2
  from tf_agents.keras_layers import rnn_wrapper
  from tf_agents.utils import test_utils
label_desc: Use image node_id 1 for calling the RNNWrapperTest obj's underlying member method code with example usage: obj.testWrapperBuild() without return types