code: def test_basic(serve_instance):
      assert (
          RAY_SERVE_ENABLE_NEW_HANDLE_API
      ), "This test needs to be run with RAY_SERVE_ENABLE_NEW_HANDLE_API=1 set."
  
      @serve.deployment
      def downstream():
          return "hello"
  
      @serve.deployment
      class Deployment:
          def __init__(self, handle: DeploymentHandle):
              self._handle = handle
              assert isinstance(self._handle, DeploymentHandle)
  
          async def __call__(self):
              ref = self._handle.remote()
              assert isinstance(ref, DeploymentResponse)
              return await ref
  
      handle: DeploymentHandle = serve.run(
          Deployment.bind(downstream.bind())
      )
      assert isinstance(handle, DeploymentHandle)
      assert handle.remote().result() == "hello"
  
imports: import sys
  import pytest
  from ray import serve
  from ray.serve._private.constants import RAY_SERVE_ENABLE_NEW_HANDLE_API
  from ray.serve.handle import DeploymentHandle, DeploymentResponse
label_desc: Use image node_id 1 for calling a global function with example usage: test_basic(serve_instance) and returns: str, unknown