public List<CalDAVCalendar> getSubscribedCalendars() {
    if (subscribedCalendars == null) {
      try {
        subscribedCalendars =
            calendarManagementService.getSubscribedCalendars(getIwc().getCurrentUser(), -1, -1);
      } catch (Exception e) {
        getLogger().log(Level.WARNING, "Error getting subscribed calendars for current user", e);
        subscribedCalendars = Collections.emptyList();
      }
    }

    getLogger().info("Calendars user is subscribed to: " + subscribedCalendars);
    return subscribedCalendars;
  }
  public Collection<CalDAVCalendar> getAvailableCalendars() {
    if (availableCalendars == null) {
      try {
        availableCalendars =
            calendarManagementService.getVisibleSubscriptions(getIwc().getCurrentUser(), -1, -1);
      } catch (Exception e) {
        getLogger().log(Level.WARNING, "Error getting available calendars for current user", e);
        availableCalendars = Collections.emptyList();
      }
    }

    getLogger().info("Available calendars: " + availableCalendars);
    return availableCalendars;
  }