code: def validate_policy_id(policy_id: str, error: bool = False) -> None:
      """Makes sure the given `policy_id` is valid.
  
      Args:
          policy_id: The Policy ID to check.
              IMPORTANT: Must not contain characters that
              are also not allowed in Unix/Win filesystems, such as: `<>:"/\\|?*`
              or a dot `.` or space ` ` at the end of the ID.
          error: Whether to raise an error (ValueError) or a warning in case of an
              invalid `policy_id`.
  
      Raises:
          ValueError: If the given `policy_id` is not a valid one and `error` is True.
      """
      if (
          not isinstance(policy_id, str)
          or len(policy_id) == 0
          or re.search('[<>:"/\\\\|?]', policy_id)
          or policy_id[-1] in (" ", ".")
      ):
          msg = (
              f"PolicyID `{policy_id}` not valid! IDs must be a non-empty string, "
              "must not contain characters that are also disallowed file- or directory "
              "names on Unix/Windows and must not end with a dot `.` or a space ` `."
          )
          if error:
              raise ValueError(msg)
          elif log_once("invalid_policy_id"):
              logger.warning(msg)
  
imports: import gymnasium
  import logging
  import numpy
  import re
  from typing import Callable, Dict, List, Mapping, Optional, Tuple, Type, Union, TYPE_CHECKING
  import tree
  import ray.cloudpickle
  from ray.rllib.models.preprocessors import ATARI_OBS_SHAPE
  from ray.rllib.policy.policy import PolicySpec
  from ray.rllib.policy.sample_batch import SampleBatch
  from ray.rllib.utils.deprecation import Deprecated
  from ray.rllib.utils.framework import try_import_tf
  from ray.rllib.utils.typing import ActionConnectorDataType, AgentConnectorDataType, AgentConnectorsOutput, PartialAlgorithmConfigDict, PolicyState, TensorStructType, TensorType
  from ray.util import log_once
  from ray.util.annotations import PublicAPI
label_desc: Use image node_id 1 for calling a global function with example usage: validate_policy_id(policy_id, error) without return types