code: def validate_environment(self, api_key):
      headers = {
          "content-type": "application/json",
      }
      if api_key:
          headers["Authorization"] = f"Bearer {api_key}"
      return headers
  
imports: from typing import Optional, Union, Any
  import types, time, json
  import httpx
  from .base import BaseLLM
  from litellm.utils import ModelResponse, Choices, Message, CustomStreamWrapper, convert_to_model_response_object, Usage
  from typing import Callable, Optional
  import aiohttp, requests
  import litellm
  from .prompt_templates.factory import prompt_factory, custom_prompt
  from openai import OpenAI, AsyncOpenAI
label_desc: Use image node_id 2 for calling the OpenAITextCompletion obj's underlying member method code with example usage: obj.validate_environment(api_key) and returns: headers