class_docstr: Fake Learner.
class_docstr_tok: ["Fake","Learner","."]
code: def __init__(
      self,
      variables: Optional[types.NestedArray] = None,
      barrier: Optional[threading.Barrier] = None,
  ):
      super().__init__(variables=variables, barrier=barrier)
      self.step_counter = 0
  
imports: import threading
  from typing import List, Mapping, Optional, Sequence, Callable, Iterator
  from acme import core
  from acme import specs
  from acme import types
  from acme import wrappers
  import dm_env
  import numpy
  import reverb
  from rlds import rlds_types
  import tensorflow
  import tree
label_desc: Use image node_id 1 to create a new Learner object from inherited base classes: core, VariableSource with example: obj = Learner(variables, barrier)