code: def startup():
      app.tokenizer = GPT2Tokenizer.from_pretrained("gpt2")
      app.model = GPT2LMHeadModel.from_pretrained("gpt2").to(app.device)
      app.ready = True
  
file_path: cortex/test/apis/realtime/text-generator/app/main.py
imports: import os
  from fastapi import FastAPI, status
  from fastapi.responses import PlainTextResponse
  from pydantic import BaseModel
  from transformers import GPT2Tokenizer, GPT2LMHeadModel
label_desc: Use image node_id 1 for calling a global function with example usage: startup() without return types