isEquivalentIterator function
Same as isEquivalentList but for Iterable.
Implementation
bool isEquivalentIterator(Iterable? it1, Iterable? it2, {bool deep = false}) {
  if (it1 == it2) return true;
  if (it1 == null) return false;
  if (it2 == null) return false;
  var length = it1.length;
  if (length != it2.length) return false;
  for (var i = 0; i < length; i++) {
    var v1 = it1.elementAt(i);
    var v2 = it2.elementAt(i);
    if (!isEquals(v1, v2, deep)) return false;
  }
  return true;
}