class_docstr: Track moving mean, std and count.
class_docstr_tok: ["Track","moving","mean",",","std","and","count","."]
docstr: Get moving standard deviation.
  
  Returns:
      Returns moving standard deviation.
docstr_tok: ["Get","moving","standard","deviation",".","Returns",":","Returns","moving","standard","deviation","."]
code: def std(self) -> float:
      """Get moving standard deviation.
  
      Returns:
          Returns moving standard deviation.
      """
      return np.sqrt(self.var)
  
imports: from gymnasium.spaces import Box, Discrete, Space
  import numpy
  from typing import List, Optional, Union
  from ray.rllib.models.action_dist import ActionDistribution
  from ray.rllib.models.catalog import ModelCatalog
  from ray.rllib.models.modelv2 import ModelV2
  from ray.rllib.policy.sample_batch import SampleBatch
  from ray.rllib.utils.annotations import override, PublicAPI
  from ray.rllib.utils.exploration.exploration import Exploration
  from ray.rllib.utils.framework import try_import_tf
  from ray.rllib.utils.from_config import from_config
  from ray.rllib.utils.tf_utils import get_placeholder
  from ray.rllib.utils.typing import FromConfigSpec, ModelConfigDict, TensorType
label_desc: Use image node_id 4 for calling the _MovingMeanStd obj's underlying member method code with example usage: obj.std() and returns: np