code: def validate_first_function_call_chunk_structure(item):
      if not isinstance(item, dict):
          raise Exception("Incorrect format")
  
      required_keys = {"id", "object", "created", "model", "choices"}
      for key in required_keys:
          if key not in item:
              raise Exception("Incorrect format")
  
      if not isinstance(item["choices"], list) or not item["choices"]:
          raise Exception("Incorrect format")
  
      required_keys_in_choices_array = {
          "index",
          "delta",
          "finish_reason",
      }
      for choice in item["choices"]:
          if not isinstance(choice, dict):
              raise Exception("Incorrect format")
          for key in required_keys_in_choices_array:
              if key not in choice:
                  raise Exception("Incorrect format")
  
          if not isinstance(choice["delta"], dict):
              raise Exception("Incorrect format")
  
          required_keys_in_delta = {"role", "content", "function_call"}
          for key in required_keys_in_delta:
              if key not in choice["delta"]:
                  raise Exception("Incorrect format")
  
          if not isinstance(choice["delta"]["function_call"], dict):
              raise Exception("Incorrect format")
  
          required_keys_in_function_call = {"name", "arguments"}
          for key in required_keys_in_function_call:
              if key not in choice["delta"]["function_call"]:
                  raise Exception("Incorrect format")
  
      return True
  
imports: import sys, os, asyncio
  import traceback
  import time, pytest
  from dotenv import load_dotenv
  import litellm
  from litellm import completion, acompletion, AuthenticationError, BadRequestError, RateLimitError, ModelResponse
label_desc: Use image node_id 29 for calling a global function with example usage: validate_first_function_call_chunk_structure(item) and returns: True