class_docstr: A wrapper that puts the previous action and reward into the observation.
class_docstr_tok: ["A","wrapper","that","puts","the","previous","action","and","reward","into","the","observation","."]
code: def reset(self) -> dm_env.TimeStep:
      # Initialize with zeros of the appropriate shape/dtype.
      action = tree.map_structure(
          lambda x: x.generate_value(), self._environment.action_spec()
      )
      reward = tree.map_structure(
          lambda x: x.generate_value(), self._environment.reward_spec()
      )
      timestep = self._environment.reset()
      new_timestep = self._augment_observation(action, reward, timestep)
      return new_timestep
  
file_path: acme/acme/wrappers/observation_action_reward.py
imports: from typing import NamedTuple
  from acme import types
  from acme.wrappers import base
  import dm_env
  import tree
label_desc: Use image node_id 1 for calling the ObservationActionRewardWrapper obj's underlying member method code with example usage: obj.reset() and returns: new_timestep