class_docstr: An environment that supports batch evaluation using clones of sub-envs.
class_docstr_tok: ["An","environment","that","supports","batch","evaluation","using","clones","of","sub-envs","."]
docstr: Restarts a single sub-environment.
  
  Args:
      index: An optional sub-env index to restart.
code: def restart_at(self, index: Optional[int] = None) -> None:
      """Restarts a single sub-environment.
  
      Args:
          index: An optional sub-env index to restart.
      """
      raise NotImplementedError
  
imports: import logging
  import gymnasium
  import numpy
  from typing import Callable, List, Optional, Tuple, Union, Set
  from ray.rllib.env.base_env import BaseEnv, _DUMMY_AGENT_ID
  from ray.rllib.utils.annotations import Deprecated, override, PublicAPI
  from ray.rllib.utils.typing import EnvActionType, EnvID, EnvInfoDict, EnvObsType, EnvType, MultiEnvDict, AgentID
  from ray.util import log_once
label_desc: Use image node_id 5 for calling the VectorEnv obj's underlying member method code with example usage: obj.restart_at(index) without return types