code: def get_xdg_dirs(self):
          # type: () -> List[str]
          
          config_dirs = getenv('XDG_CONFIG_DIRS', '')
          if config_dirs:
              self._log.debug('XDG_CONFIG_DIRS is set to %r', config_dirs)
              output = []
              for path in reversed(config_dirs.split(':')):
                  output.append(join(path, self.group_name, self.app_name))
              return output
          return ['/etc/xdg/%s/%s' % (self.group_name, self.app_name)]
docs: Returns a list of paths specified by the XDG_CONFIG_DIRS environment
          variable or the appropriate default.
  
          The list is sorted by precedence, with the most important item coming
          *last* (required by the existing config_resolver logic).