docs: def get_plain_logname(base_name, root_dir, enable_json):
      """
      we nest all plain logs to prevent double log shipping
      """
      if enable_json:
          nested_dir = os.path.join(root_dir, 'plain')
          if os.path.exists(root_dir) and not os.path.exists(nested_dir):
              os.mkdir(nested_dir)
          root_dir = nested_dir
      return os.path.join(root_dir, '{}.log'.format(base_name))