code: def test_img_gen_on_router():
      litellm.set_verbose = True
      try:
          model_list = [
              {
                  "model_name": "dall-e-3",
                  "litellm_params": {
                      "model": "dall-e-3",
                  },
              },
              {
                  "model_name": "dall-e-3",
                  "litellm_params": {
                      "model": "azure/dall-e-3-test",
                      "api_version": "2023-12-01-preview",
                      "api_base": os.getenv("AZURE_SWEDEN_API_BASE"),
                      "api_key": os.getenv("AZURE_SWEDEN_API_KEY"),
                  },
              },
          ]
          router = Router(model_list=model_list)
          response = router.image_generation(
              model="dall-e-3", prompt="A cute baby sea otter"
          )
          print(response)
          assert len(response.data) > 0
          router.reset()
      except litellm.RateLimitError as e:
          pass
      except Exception as e:
          traceback.print_exc()
          pytest.fail(f"Error occurred: {e}")
  
imports: import sys, os, time
  import traceback, asyncio
  import pytest
  import litellm
  from litellm import Router
  from concurrent.futures import ThreadPoolExecutor
  from collections import defaultdict
  from dotenv import load_dotenv
label_desc: Use image node_id 7 for calling a global function with example usage: test_img_gen_on_router() without return types