code: def create_list_query(self, tokens):
          
          if not tokens[Keyword.SERIES]:
              # A list series keyword is allowed
              # without a series name or regex
              tokens[Keyword.SERIES] = ''
          return ListQuery(self.parse_keyword(Keyword.SERIES, tokens))
docs: Parse tokens of list query
          :param tokens: A list of InfluxDB query tokens