code: def kill_process_children(pid):
      
      if sys.platform == "darwin":
          kill_process_children_osx(pid)
      elif sys.platform == "linux":
          kill_process_children_unix(pid)
      else:
          pass
docs: Find and kill child processes of a process.
  
      :param pid: PID of parent process (process ID)
      :return: Nothing