class_docstr: Slim wrapper around an agent/optimizer pair.
class_docstr_tok: ["Slim","wrapper","around","an","agent\/optimizer","pair","."]
code: def __init__(self, agent: Agent, opt_update):
      self._agent = agent
      self._opt_update = opt_update
  
imports: import functools
  import queue
  import threading
  from typing import Any, Callable, NamedTuple
  from absl import app
  from absl import logging
  from bsuite.environments import catch
  import dm_env
  import haiku
  import jax
  import jax.numpy
  import numpy
  import optax
  import rlax
label_desc: Use image node_id 1 to create a new Learner object  with example: obj = Learner(agent, opt_update)