code: def test_timeline_request(shutdown_only):
      context = ray.init()
      dashboard_url = f"http://{context['webui_url']}"
  
      @ray.remote
      def f():
          pass
  
      ray.get([f.remote() for _ in range(5)])
  
      # Make sure the API works.
      def verify():
          resp = requests.get(f"{dashboard_url}/api/v0/tasks/timeline")
          resp.raise_for_status()
          assert resp.json(), "No result has returned"
          return True
  
      wait_for_condition(verify, timeout=10)
  
imports: import asyncio
  import json
  import os
  import sys
  from pathlib import Path
  import tempfile
  from collections import defaultdict
  from ray._private.test_utils import check_call_subprocess
  import ray
  import requests
  import pytest
  from ray._private.profiling import chrome_tracing_dump
  from ray.util.state import get_actor, list_tasks, list_actors, list_workers, list_nodes
  from ray._private.test_utils import wait_for_condition
label_desc: Use image node_id 2 for calling a global function with example usage: test_timeline_request(shutdown_only) and returns: True