def _GetCurrentControlSet(self, key_path_suffix):
select_key_path = '<STR_LIT>'<EOL>select_key = self.GetKeyByPath(select_key_path)<EOL>if not select_key:<EOL><INDENT>return None<EOL><DEDENT>control_set = None<EOL>for value_name in ('<STR_LIT>', '<STR_LIT>', '<STR_LIT>'):<EOL><INDENT>value = select_key.GetValueByName(value_name)<EOL>if not value or not value.DataIsInteger():<EOL><INDENT>continue<EOL><DEDENT>control_set = value.GetDataAsObject()<EOL>if control_set > <NUM_LIT:0> or control_set <= <NUM_LIT>:<EOL><INDENT>break<EOL><DEDENT><DEDENT>if not control_set or control_set <= <NUM_LIT:0> or control_set > <NUM_LIT>:<EOL><INDENT>return None<EOL><DEDENT>control_set_path = '<STR_LIT>'.format(<EOL>control_set)<EOL>key_path = '<STR_LIT>'.join([control_set_path, key_path_suffix])<EOL>return self.GetKeyByPath(key_path)<EOL>
Virtual key callback to determine the current control set.

        Args:
          key_path_suffix (str): current control set Windows Registry key path
              suffix with leading path separator.

        Returns:
          WinRegistryKey: the current control set Windows Registry key or None
              if not available.