docs: def build_userlist(self, userlist_node):
          """parse `userlist` sections, and return a config.Userlist"""
          proxy_name = userlist_node.userlist_header.proxy_name.text
          config_block_lines = self.__build_config_block(
              userlist_node.config_block)
          return config.Userlist(
              name=proxy_name,
              config_block=config_block_lines)