code: def from_file(tokens_file: str) -> "Tokens":
      with open(tokens_file, "r", encoding="utf-8") as f:
          log.info(f"tokens loaded from {tokens_file}")
          return Tokens(json.load(f))
  
imports: from typing import Optional, Dict, Tuple
  import base64
  import collections.abc
  import os
  import json
  import logging
  from hailtop.config import get_deploy_config
  from hailtop.utils import first_extant_file
label_desc: Use image node_id 3 for calling the Tokens obj's underlying member method code with example usage: obj.from_file(tokens_file) and returns: Tokens