code: def test_http_user_bring_own_driver_route_prefix(serve_instance):
      m1 = Model.bind(1)
      serve_dag = Driver.options(route_prefix="/hello").bind(m1)
  
      deployments = pipeline_build(serve_dag)
      ingress_deployment = get_and_validate_ingress_deployment(
          deployments
      )
      assert ingress_deployment.route_prefix == "/hello"
      for deployment in deployments[:-1]:
          assert deployment.route_prefix is None
  
file_path: ray/python/ray/serve/tests/test_deployment_graph_ingress.py
imports: import sys
  import pytest
  from ray import serve
  from ray.serve._private.deployment_graph_build import build
  from ray.serve._private.deployment_graph_build import get_and_validate_ingress_deployment
label_desc: Use image node_id 3 for calling a global function with example usage: test_http_user_bring_own_driver_route_prefix(serve_instance) without return types