code: def test_custom_io_descriptor():
      svc = bentoml.Service("test")
  
      @svc.api(input=CustomDescriptor(), output=CustomDescriptor())
      def descriptor_test_api(inp):
          return inp
  
      svc.asgi_app
  
imports: from __future__ import annotations
  import typing
  from typing import TYPE_CHECKING
  from starlette.requests import Request
  from starlette.responses import Response
  import bentoml
  from bentoml._internal.service.openapi import SUCCESS_DESCRIPTION
  from bentoml._internal.service.openapi.specification import MediaType
  from bentoml._internal.service.openapi.specification import Schema
  from bentoml._internal.utils.http import set_cookies
  from bentoml.exceptions import BentoMLException
  from bentoml.io import IODescriptor
label_desc: Use image node_id 1 for calling a global function with example usage: test_custom_io_descriptor() and returns: inp