code: def _sentinel_visitor(path, key, value):
      """If `value` is a `Sentinel` return the value it represents. Else `default_visit`"""
      if isinstance(value, Sentinel):
          return (key, value.retrieve_by_sentinel())
      return (key, value)
  
file_path: hyperparameter_hunter/hyperparameter_hunter/sentinels.py
imports: from hyperparameter_hunter.data.data_core import BaseDataset
  from hyperparameter_hunter.settings import G
  from hyperparameter_hunter.utils.boltons_utils import remap
  from abc import ABCMeta, abstractmethod
label_desc: Use image node_id 1 for calling a global function with example usage: _sentinel_visitor(path, key, value) and returns: key,  value, key,  value