code: def _test_all(self, root_key, subkeystr="sub_key"):
      self._write_test_data(root_key, subkeystr)
      self._read_test_data(root_key, subkeystr)
      self._delete_test_data(root_key, subkeystr)
  
imports: import gc
  import os, sys, errno
  import threading
  import unittest
  from platform import machine, win32_edition
  from test.support import cpython_only, import_helper
  from winreg import *
label_desc: Use image node_id 6 for calling the BaseWinregTests obj's underlying member method code with example usage: obj._test_all(root_key, subkeystr) without return types