code: def test_kill_child_processes(m_get_child_process_ids, m_os):
      m_get_child_process_ids.return_value = ["child_pids"]
      sagemaker.local.utils.kill_child_processes("pid")
      m_os.kill.assert_called_with("child_pids", 15)
  
imports: from __future__ import absolute_import
  import os
  import errno
  import pytest
  import json
  from mock import patch, Mock, mock_open
  import sagemaker.local.utils
  from sagemaker.session_settings import SessionSettings
label_desc: Use image node_id 7 for calling a global function with example usage: test_kill_child_processes(m_get_child_process_ids, m_os) without return types