code: @Cached
      @DontLabel
      public Rule sequence(final Object[] rules)
      {
          Objects.requireNonNull(rules);
          return rules.length == 1 ? toRule(rules[0])
              : new SequenceMatcher(toRules(rules));
      }
docs: Match a given set of rules, exactly once
  
  @param rules the rules
  @return a rule