code: public Map<String, Integer> getRouteHeadwaysForStop (String stop_id, LocalDate date, LocalTime from, LocalTime to) {
          Map<String, Integer> routeHeadwayMap = new HashMap<>();
          List<Route> routes = feed.patterns.values().stream()
                  .filter(p -> p.orderedStops.contains(stop_id))
                  .map(p -> feed.routes.get(p.route_id))
                  .collect(Collectors.toList());
  
          for (Route route : routes) {
              routeHeadwayMap.put(route.route_id, getHeadwayForStopByRoute(stop_id, route.route_id, date, from, to));
          }
          return routeHeadwayMap;
      }
docs: Get the route headway for a given service date at a stop over a time window, in seconds