docs: public static List<Map<String, Object>> nest(String key, Map<String, Object> map) {
          List<Map<String, Object>> result = new ArrayList<Map<String, Object>>();
          String patternString = MessageFormat.format("^{0}\\.([0-9]*)\\.(.*)", Pattern.quote(key));
          Pattern pattern = Pattern.compile(patternString);
          for (Map.Entry<String, Object> entry : map.entrySet()) {
              String k = entry.getKey();
              Matcher matcher = pattern.matcher(k);
              if (matcher.matches()) {
                  int base = 0;
                  processMatch(result, entry.getValue(), matcher, base);
              }
          }
          return result;
      }