code: def call(self, observations, network_state=None):
      return self.var + observations, self.state + network_state
  
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 3 for calling the MockStateFullNetwork obj's underlying member method code with example usage: obj.call(observations, network_state) and returns: unknown,  unknown