code: def flow_context(gateway_port):
      start_event = Event()
      stop_event = Event()
      p = Process(
          target=ws_flow,
          args=(start_event, stop_event, gateway_port),
      )
      p.start()
      start_event.wait()
      yield
      stop_event.set()
      p.join()
  
file_path: jina/tests/integration/websocket_gateway/test_subprotocols.py
imports: import asyncio
  import time
  from multiprocessing import Event, Process
  import aiohttp
  import pytest
  from jina import DocumentArray, Executor, Flow, requests
  from jina.helper import random_port
  from jina.types.request.data import DataRequest
label_desc: Use image node_id 6 for calling a global function with example usage: flow_context(gateway_port) without return types