code: def testAllZeroLengthStateSpecsShowAsEmptyState(self):
      sequential = sequential_lib.Sequential(
          [
              nest_map.NestMap(
                  {
                      "a": tf.keras.layers.Dense(2),
                      "b": tf.keras.layers.Dense(3),
                  }
              )
          ]
      )
      self.assertEqual(sequential.state_spec, ())
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import os
  from absl import flags
  import numpy
  import tensorflow
  import tensorflow_probability
  from tf_agents.distributions import utils
  from tf_agents.keras_layers import dynamic_unroll_layer
  from tf_agents.keras_layers import inner_reshape
  from tf_agents.networks import nest_map
  from tf_agents.networks import network
  from tf_agents.networks import sequential
  from tf_agents.policies import actor_policy
  from tf_agents.policies import policy_saver
  from tf_agents.specs import tensor_spec
  from tf_agents.trajectories import time_step
  from tf_agents.utils import common
  from tf_agents.utils import test_utils
label_desc: Use image node_id 5 for calling the SequentialTest obj's underlying member method code with example usage: obj.testAllZeroLengthStateSpecsShowAsEmptyState() without return types