sclass HFlagsWithCount {
  new MultiSet<S> countryMultiSet;
  Map<S, Int> countriesByCount;
  
  S headStuff() { ret hcss_flags(); }
  
  void addCountry(S country) {
    if (nempty(country))
      countryMultiSet.add(country);
  }
  
  S html() {
    countriesByCount = sortedByValue(countryMultiSet.asMap());
  
    ret joinWithSpace(
      map(countriesByCount, (country, n) -> 
        div("", class := "iti__flag iti__" + lower(country),
          style := "display: inline-block",
          title := makeTitle(country, n))
          + appendBracketedCountUnlessOne(n)));
  }
  
  S makeTitle(S country, int n) {
    ret nVisitors(n) + " from " + country;
  }
}