function fn() {
  var map = {},
      set = [];

  for (var i = 0; i < 250; i++) {
    map[i] = i;
    set.push(i);
  }

  map.foo = 'bar';
  set.push('bar');
  return ('foo' in map) && set.indexOf('bar') >= 0;
}

assertEqual(fn(), true);
test(fn);