code: def _test_tensorboard(view_url):
      tb_init_url = f"{view_url}/tb/0/"
      sys.stdout.write(f"Initializing TensorBoard at {tb_init_url}\n")
      _urlread(tb_init_url)
      runs_url = f"{view_url}/tb/0/data/runs"
      sys.stdout.write(f"Testing {runs_url}\n")
      runs_str = _urlread(runs_url)
      runs = json.loads(runs_str.decode())
      sys.stdout.write(f" - Got {len(runs)} TensorBoard run(s)\n")
      sys.stdout.flush()
  
file_path: guildai/guild/commands/view_tester.py
imports: import json
  import logging
  import sys
  import threading
  import time
  from guild import util
label_desc: Use image node_id 5 for calling a global function with example usage: _test_tensorboard(view_url) without return types