code: def make_ensemble_actor_core(
      networks: mbop_networks.MBOPNetworks,
      mppi_config: mppi.MPPIConfig,
      environment_spec: specs.EnvironmentSpec,
      mean_std: Optional[running_statistics.NestedMeanStd] = None,
      use_round_robin: bool = True,
  ) -> ActorCore:
      """Creates an actor core that uses ensemble models.
  
      Args:
        networks: MBOP networks.
        mppi_config: Planner hyperparameters.
        environment_spec: Used to initialize the initial trajectory data structure.
        mean_std: Used to undo normalization if the networks trained normalized.
        use_round_robin: Whether to use round robin or mean to calculate the policy
          prior over the ensemble members.
  
      Returns:
        A recurrent actor core.
      """
      world_model = models.make_ensemble_world_model(
          networks.world_model_network
      )
      policy_prior = models.make_ensemble_policy_prior(
          networks.policy_prior_network,
          environment_spec,
          use_round_robin=use_round_robin,
      )
      n_step_return = models.make_ensemble_n_step_return(
          networks.n_step_return_network
      )
  
      return make_actor_core(
          mppi_config,
          world_model,
          policy_prior,
          n_step_return,
          environment_spec,
          mean_std,
      )
  
file_path: acme/acme/agents/jax/mbop/acting.py
imports: from typing import List, Mapping, Optional, Tuple
  from acme import adders
  from acme import core
  from acme import specs
  from acme.agents.jax import actor_core
  from acme.agents.jax import actors
  from acme.agents.jax.mbop import models
  from acme.agents.jax.mbop import mppi
  from acme.agents.jax.mbop import networks
  from acme.jax import networks
  from acme.jax import running_statistics
  from acme.jax import variable_utils
  import jax
  from jax import numpy
label_desc: Use image node_id 2 for calling a global function with example usage: make_ensemble_actor_core(networks, mppi_config, environment_spec, mean_std, use_round_robin) and returns: make_actor_core