code: def read_environ(cls):
      env_vars = {}
      for e in _OpenAIEnvVar:
          if value := os.getenv(e.value):
              env_vars[e.value] = value
      return env_vars
  
imports: import json
  import os
  import time
  from contextlib import contextmanager
  from enum import Enum
  from typing import NamedTuple, Optional
  from unittest import mock
  import requests
  import mlflow
label_desc: Use image node_id 2 for calling the _OpenAIEnvVar obj's underlying member method code with example usage: obj.read_environ(cls) and returns: env_vars