Your task is to make a function that can take any non-negative integer as an argument and return it with its digits in descending order. Essentially, rearrange the digits to create the highest possible number.

Examples:

Input: 42145 Output: 54421

Input: 145263 Output: 654321

Input: 123456789 Output: 987654321

int descendingOrder(n) {
  List<String> biggest = n.toString().split('').toList()..sort((a, b) => b.compareTo(a));
  return int.parse(biggest.join());
}