code: def validate_environment(self, api_key, headers):
      default_headers = {
          "content-type": "application/json",
      }
      if api_key and headers is None:
          default_headers[
              "Authorization"
          ] = f"Bearer {api_key}"  # Huggingface Inference Endpoint default is to accept bearer tokens
          headers = default_headers
      elif headers:
          headers = headers
      else:
          headers = default_headers
      return headers
  
imports: import os, copy, types
  import json
  from enum import Enum
  import httpx, requests
  from .base import BaseLLM
  import time
  import litellm
  from typing import Callable, Dict, List, Any
  from litellm.utils import ModelResponse, Choices, Message, CustomStreamWrapper, Usage
  from typing import Optional
  from .prompt_templates.factory import prompt_factory, custom_prompt
label_desc: Use image node_id 2 for calling the Huggingface obj's underlying member method code with example usage: obj.validate_environment(api_key, headers) and returns: headers