code: def testFixedPolicySingle(self):
      observations = tf.constant([1, 2], dtype=tf.float32)
      time_step = ts.restart(observations)
      action_step = self._policy.action(time_step)
      distribution_step = self._policy.distribution(time_step)
      mode = distribution_step.action.mode()
  
      self.evaluate(tf.compat.v1.global_variables_initializer())
      self.assertAllEqual(
          self.evaluate(action_step.action), [self._fixed_action]
      )
      self.assertAllEqual(self.evaluate(mode), [self._fixed_action])
  
file_path: agents/tf_agents/policies/fixed_policy_test.py
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import numpy
  import tensorflow
  from tf_agents.policies import fixed_policy
  from tf_agents.specs import tensor_spec
  from tf_agents.trajectories import time_step
  from tf_agents.utils import test_utils
label_desc: Use image node_id 2 for calling the FixedPolicyTest obj's underlying member method code with example usage: obj.testFixedPolicySingle() without return types