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 _augment_observation(
      self,
      action: types.NestedArray,
      reward: types.NestedArray,
      timestep: dm_env.TimeStep,
  ) -> dm_env.TimeStep:
      oar = OAR(
          observation=timestep.observation, action=action, reward=reward
      )
      return timestep._replace(observation=oar)
  
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 3 for calling the ObservationActionRewardWrapper obj's underlying member method code with example usage: obj._augment_observation(action, reward, timestep) and returns: timestep