code: def _path(token_prefix):
      # TODO make this a MF config variable
      if os.environ.get("METAFLOW_TOKEN_HOME"):
          home = os.environ.get("METAFLOW_TOKEN_HOME")
      else:
          home = os.environ.get("METAFLOW_HOME", "~/.metaflowconfig")
      return os.path.expanduser("%s/%s" % (home, token_prefix))
  
file_path: metaflow/metaflow/plugins/aws/step_functions/production_token.py
imports: import os
  import json
  import random
  import string
  import zlib
  from itertools import dropwhile, islice
  from metaflow.util import to_bytes
label_desc: Use image node_id 4 for calling a global function with example usage: _path(token_prefix) and returns: os