class_docstr: BC learner.
  
  This is the learning component of a BC agent. It takes a Transitions iterator
  as input and implements update functionality to learn from this iterator.
code: def get_variables(
      self, names: List[str]
  ) -> List[networks_lib.Params]:
      variables = {
          "policy": utils.get_from_first_device(
              self._state.policy_params
          ),
      }
      return [variables[name] for name in names]
  
imports: import time
  from typing import Dict, List, NamedTuple, Optional, Tuple, Union, Iterator
  import acme
  from acme import types
  from acme.agents.jax.bc import losses
  from acme.agents.jax.bc import networks
  from acme.jax import networks
  from acme.jax import utils
  from acme.utils import counting
  from acme.utils import loggers
  import jax
  import jax.numpy
  import optax
label_desc: Use image node_id 3 for calling the BCLearner obj's underlying member method code with example usage: obj.get_variables(names) and returns: unknown