select random from set

randomEmail.dart

import 'dart:math';

void main() {
  var _emailSet = new Set.from([
    '',
    ''
  ]);

  final _random = new Random();

  for (int i = 0; i < 5; i++) {
    var element = _randomElement(_emailSet, _random);
    
    _emailSet.remove(element);
    print(element);
  }
}

_randomElement(Set emailSet, Random random) {
  return emailSet.elementAt(random.nextInt(emailSet.length));
}