code: def _from_file(
      cls, path: str = DEFAULT_TRIAL_INFO_PATH
  ) -> Optional["TrialInfo"]:
      if not os.path.exists(path):
          return None
      with open(path) as f:
          return cls(**json.load(f))
  
imports: import json
  import os
  from typing import Any, Dict, Iterable, List, Optional, Union
  from determined import gpu
label_desc: Use image node_id 4 for calling the TrialInfo obj's underlying member method code with example usage: obj._from_file(cls, path) and returns: None, cls