code: def test_gpt_assistant_existing_no_instructions():
      """
      Test function to check if the GPTAssistantAgent can retrieve instructions for an existing assistant
      even if the assistant was created with no instructions initially.
      """
      name = "For test_gpt_assistant_existing_no_instructions"
      instructions = "This is a test #1"
  
      assistant = GPTAssistantAgent(
          name,
          instructions=instructions,
          llm_config={
              "config_list": config_list,
          },
      )
  
      assistant_id = assistant.assistant_id
  
      # create a new assistant with the same ID but no instructions
      assistant = GPTAssistantAgent(
          name,
          llm_config={
              "config_list": config_list,
              "assistant_id": assistant_id,
          },
      )
  
      instruction_match = (
          assistant.get_assistant_instructions() == instructions
      )
      assistant.delete_assistant()
      assert instruction_match is True
  
file_path: autogen/test/agentchat/contrib/test_gpt_assistant.py
imports: import pytest
  import os
  import sys
  import autogen
  from autogen import OpenAIWrapper
  from conftest import skip_openai
  from test_assistant_agent import KEY_LOC, OAI_CONFIG_LIST
label_desc: Use image node_id 5 for calling a global function with example usage: test_gpt_assistant_existing_no_instructions() without return types