code: def test_flatten_undefined_shapes_in_tffun(self):
      batch_squash = utils.BatchSquash(2)
  
      @tf.function
      def tf_fn():
          # Construct a tensor with some unknown shapes.
          x_default = tf.random.uniform([2, 2, 128, 128, 3])
          input_tensor = tf.compat.v1.placeholder_with_default(
              x_default, shape=[2, 2, None, None, None]
          )
          flat = batch_squash.flatten(input_tensor)
  
          self.assertAllEqual((4, None, None, None), flat.shape)
  
      tf_fn()
  
file_path: agents/tf_agents/networks/utils_test.py
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import tensorflow
  from tf_agents.keras_layers import permanent_variable_rate_dropout
  from tf_agents.networks import utils
label_desc: Use image node_id 5 for calling the NetworkUtilsTest obj's underlying member method code with example usage: obj.test_flatten_undefined_shapes_in_tffun() without return types