class_docstr: Observer that tracks statstics of continuous actions taken by the agent.
  
  Assumes the action is a np.ndarray, and for each dimension in the action,
  calculates some useful statistics for a particular episode.
code: def __init__(self):
      self._actions = None
  
file_path: acme/acme/utils/observers/action_metrics.py
imports: from typing import Dict
  from acme.utils.observers import base
  import dm_env
  import numpy
label_desc: Use image node_id 1 to create a new ContinuousActionObserver object from inherited base classes: base with example: obj = ContinuousActionObserver()