docs: static Matcher combineAdjacentCharSeqs(Matcher matcher) {
      if (matcher instanceof SeqMatcher) {
        List<Matcher> matchers = matcher.<SeqMatcher>as().matchers();
        List<Matcher> ms = new ArrayList<>();
        CharSeqMatcher cs1 = null;
        for (Matcher m : matchers) {
          if (m instanceof CharSeqMatcher) {
            if (cs1 == null) {
              cs1 = m.as();
            } else {
              CharSeqMatcher cs2 = m.as();
              cs1 = new CharSeqMatcher(cs1.pattern() + cs2.pattern());
            }
          } else {
            if (cs1 != null) {
              ms.add(cs1);
              cs1 = null;
            }
            ms.add(m);
          }
        }
        if (cs1 != null) {
          ms.add(cs1);
        }
        return SeqMatcher.create(ms);
      }
      return matcher;
    }