code: def test_model_added():
      test_cache = DualCache()
      least_busy_logger = LeastBusyLoggingHandler(
          router_cache=test_cache, model_list=[]
      )
      kwargs = {
          "litellm_params": {
              "metadata": {
                  "model_group": "gpt-3.5-turbo",
                  "deployment": "azure/chatgpt-v-2",
              },
              "model_info": {"id": "1234"},
          }
      }
      least_busy_logger.log_pre_api_call(
          model="test", messages=[], kwargs=kwargs
      )
      request_count_api_key = f"gpt-3.5-turbo_request_count"
      assert test_cache.get_cache(key=request_count_api_key) is not None
  
file_path: litellm/litellm/tests/test_least_busy_routing.py
imports: import sys, os, asyncio, time, random
  import traceback
  from dotenv import load_dotenv
  import os
  import pytest
  from litellm import Router
  import litellm
  from litellm.router_strategy.least_busy import LeastBusyLoggingHandler
  from litellm.caching import DualCache
label_desc: Use image node_id 1 for calling a global function with example usage: test_model_added() without return types