docs: public IdRange[] parseIdRange(ImapRequestLineReader request)
              throws ProtocolException {
          CharacterValidator validator = new MessageSetCharValidator();
          String nextWord = consumeWord(request, validator);
  
          int commaPos = nextWord.indexOf(',');
          if (commaPos == -1) {
              return new IdRange[]{IdRange.parseRange(nextWord)};
          }
  
          List<IdRange> rangeList = new ArrayList<>();
          int pos = 0;
          while (commaPos != -1) {
              String range = nextWord.substring(pos, commaPos);
              IdRange set = IdRange.parseRange(range);
              rangeList.add(set);
  
              pos = commaPos + 1;
              commaPos = nextWord.indexOf(',', pos);
          }
          String range = nextWord.substring(pos);
          rangeList.add(IdRange.parseRange(range));
          return rangeList.toArray(new IdRange[rangeList.size()]);
      }