code: def done_callback(idx):
      with cv:
          done_threads.append(idx)
          cv.notify()
  
file_path: byteps/launcher/launch.py
imports: from __future__ import print_function
  import os
  import re
  import subprocess
  import threading
  import sys
  import time
  from functools import reduce
label_desc: Use image node_id 5 for calling a global function with example usage: done_callback(idx) without return types