code: public List<Service> getServicesForDate (LocalDate date) {
          String dateString = date.format(dateFormatter);
          SortedSet<Tuple2<String, String>> index = this.servicesPerDate
                  .subSet(new Tuple2<>(dateString, null), new Tuple2(dateString, Fun.HI));
  
          return index.stream()
                  .map(tuple -> this.services.get(tuple.b))
                  .collect(Collectors.toList());
      }
docs: Get list of services for each date of service.