code: def test_mix_sync_async_handle(serve_instance):
      # TODO: (jiaodong) Add complex multi-deployment tests from ray DAG.
      pass
  
file_path: ray/python/ray/serve/tests/test_deployment_node.py
imports: import pytest
  import ray
  from ray import serve
  from ray.serve._private.deployment_node import DeploymentNode
label_desc: Use image node_id 1 for calling a global function with example usage: test_mix_sync_async_handle(serve_instance) without return types