docstr: Exercise `reset` and `step`. Ensure correct shapes are returned.
docstr_tok: ["Exercise","`","reset","`","and","`","step","`",".","Ensure","correct","shapes","are","returned","."]
code: def testObservationAndRewardShapes(
      self, batch_size, observation_shape
  ):
      """Exercise `reset` and `step`. Ensure correct shapes are returned."""
      env = ZerosEnvironment(
          batch_size=batch_size, observation_shape=observation_shape
      )
  
      @common.function
      def observation_and_reward():
          observation = env.reset().observation
          reward = env.step(tf.zeros(batch_size)).reward
          return observation, reward
  
      observation, reward = observation_and_reward()
  
      expected_observation = np.zeros([batch_size] + observation_shape)
      expected_reward = np.zeros(batch_size)
  
      np.testing.assert_array_almost_equal(
          expected_observation, self.evaluate(observation)
      )
      np.testing.assert_array_almost_equal(
          expected_reward, self.evaluate(reward)
      )
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  from absl.testing import parameterized
  import numpy
  import tensorflow
  from tf_agents.bandits.environments import bandit_tf_environment
  from tf_agents.specs import tensor_spec
  from tf_agents.trajectories import time_step
  from tf_agents.utils import common
label_desc: Use image node_id 1 for calling the BanditTFEnvironmentTest obj's underlying member method code with example usage: obj.testObservationAndRewardShapes(batch_size, observation_shape) and returns: observation,  reward