get_max_rank method

Implementation

double get_max_rank(){
  List<double> lst = [];
  for (var c in choices.values ){
    lst.add(c.interranking);
  }
  double max = lst.reduce((a, b) => a > b ? a : b);
  /*
  List<Choice> Mmax = choices.values.toList();
  Mmax.sort((a,b) => b.interranking.compareTo(a.interranking));
  print(Mmax.map((e)=> e.interranking).toList());
  */
  return max;

}