code: def test_empty_state(self):
      input_spec = tf.TensorSpec([], tf.float32, "inputs")
      net = MockStateFullNetwork(input_spec, ())
      self.assertEqual(input_spec, net.input_tensor_spec)
      self.assertEqual((), net.state_spec)
      net.create_variables()
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  from absl.testing import parameterized
  import tensorflow
  import tensorflow_probability
  from tf_agents import specs
  from tf_agents.distributions import utils
  from tf_agents.keras_layers import rnn_wrapper
  from tf_agents.networks import network
  from tf_agents.utils import common
label_desc: Use image node_id 2 for calling the StateFullNetworkTest obj's underlying member method code with example usage: obj.test_empty_state() without return types