class_docstr: Keeps track of a running mean for seen states
class_docstr_tok: ["Keeps","track","of","a","running","mean","for","seen","states"]
code: def reset_buffer(self) -> None:
      self.buffer = tree.map_structure(
          lambda s: RunningStat(s), self.shape
      )
  
imports: import logging
  import threading
  import numpy
  import tree
  from ray.rllib.utils.annotations import DeveloperAPI
  from ray.rllib.utils.deprecation import Deprecated
  from ray.rllib.utils.numpy import SMALL_NUMBER
  from ray.rllib.utils.typing import TensorStructType
  from ray.rllib.utils.serialization import _serialize_ndarray, _deserialize_ndarray
  from ray.rllib.utils.deprecation import deprecation_warning
label_desc: Use image node_id 2 for calling the MeanStdFilter obj's underlying member method code with example usage: obj.reset_buffer() without return types